This may or may not apply to you but this has happened to me twice:  I purchased a handgun (one from a private individual, one from a LGS), applied for the permit (s), picked up permit (s), got the handgun (s)  and took it/them to HPD.  At the registration window (once HPD had possession of the handgun) I was informed that the handgun was not registered to the person/LGS that sold it to me.  HPD contacted both sellers and I believe both guns were subsequently destroyed.  I got my money back from both sellers (no problems there) and I wasn't in any trouble with HPD but HPD will make sure they get control of the firearm before informing you that for whatever reason you can't take possession of it.

So, if the seller can show you his/her registration for the firearm in question there should be no problems transferring the firearm.  If they can't remember if it was legally registered/transferred to themselves in the first place, there may or may not be a problem.

Thank you for this anecdote because this is exactly what I fear may happen for the said pistol that is missing registration paper.  I'd rather not mess with and risk having it needlessly confiscated if it wasn't registered correctly. 
BUT - they would not issue the Permit if the registrant on the permit does not match their file right?   So, if I WERE to pick up the Permit, then pick up the pistol and register it same day, I would assume it would not run into this issue and thusly cause it to be confiscated, correct?  Because the permit to acquire was approved and the registered owner was verified during that process.... right?

If the seller has not registered it, all they need to do is go to HPD and register as an out of state "import" that they already owned.  After that, the sale is good to go.

HOWEVER, if the gun was previously registered to someone prior to the seller gaining possession, this is not a good solution.  If they find the registration on file, it'll raise some tough questions.  In this case, it would be a good idea for the seller to ask HPD what firearms they have registered for them,  If the gun begin sold isn't listed, contact the person who sold it to the seller and see if they are in HPD's records as the owner.  If so, do the transfer.registration from previous seller to new seller, then from new seller to you/buyer.  Or, you can short-circuit that and transfer from the previous owner to you directly bypassing the current seller -- if everyone is agreeable.

Don't volunteer any information to HPD.  Tell them just enough to find out whether the gun is registered and to whom.

If all this seems like too much effort and risk, then it's probably time to look elsewhere.

If the seller has not registered it, all they need to do is go to HPD and register as an out of state "import" that they already owned.  After that, the sale is good to go.

HOWEVER, if the gun was previously registered to someone prior to the seller gaining possession, this is not a good solution.  If they find the registration on file, it'll raise some tough questions.  In this case, it would be a good idea for the seller to ask HPD what firearms they have registered for them,  If the gun begin sold isn't listed, contact the person who sold it to the seller and see if they are in HPD's records as the owner.  If so, do the transfer.registration from previous seller to new seller, then from new seller to you/buyer.  Or, you can short-circuit that and transfer from the previous owner to you directly bypassing the current seller -- if everyone is agreeable.

Don't volunteer any information to HPD.  Tell them just enough to find out whether the gun is registered and to whom.

If all this seems like too much effort and risk, then it's probably time to look elsewhere.

Got it, agreed, thank you

That sounds about right, when I buy guns from an LGS I do have the option of registering them online.  I usually take it in to get registered but the lines have been so long that this next one will be registered online--so what if they're saying it takes about a month now for online registration, that beats standing in line for hours, worrying about parking and possibly having the door shut in your face after going through all that.

Do I have to complete the entire questionnaire and medical waivers that are attached to the permit to acquire application?  for each pistol?  and even though I own other firearms/pistols already?

Do I have to complete the entire questionnaire and medical waivers that are attached to the permit to acquire application?  for each pistol?  and even though I own other firearms/pistols already?

Whichever option is more cumbersome, repetitive and time consuming is the right one.

HPD is not there to make gun ownership easier.

Also, think about the "common sense gun control" reasons for the process.  Part of the reason for getting a permit for every handgun purchase is to verify that nothing has changed to affect your fitness to own or possess firearms.  So, yeah, if you buy a handgun every other month in a year, that gives HPD half a dozen opportunities to deny you and confiscate what you already have in your gun safe.

RAPBACK was intended to be sort of a "rolling background check" system, where instead of waiting until you try to acquire another firearm before checking up on you, all your LE encounters will be reported proactively to HPD, allowing them the opportunity to confiscate your guns if the reported situation warrants it.

BUT - they would not issue the Permit if the registrant on the permit does not match their file right?   So, if I WERE to pick up the Permit, then pick up the pistol and register it same day, I would assume it would not run into this issue and thusly cause it to be confiscated, correct?  Because the permit to acquire was approved and the registered owner was verified during that process.... right?

Sorry, but in reviewing this thread I may have not made myself clear about those 2 situations--in both cases HPD probably knew at the time that the pistol wasn't properly registered to the person who sold it to me (they do check registrations on the computer when you apply).  They issued the permit anyway and I brought the firearms to them, at which time they then confiscated the pistols.  AFTER they had the pistols in hand, they then called the seller and I was not privy to what transpired afterwards.  So again, if the firearm is NOT properly registered to the seller, I believe HPD will make you jump through the hoops, bring the firearm to them, then they'll confiscate it.

If it is a "pre-94" long gun that didn't have to be registered they will register it to you as "no previous registration" as long as it is not stolen (of course).

So, in your situation if the seller can't remember if he registered the handgun in the first place you do run a risk of having it confiscated if it wasn't properly registered.  HPD will not tell you who is the registered owner of firearm.

Sorry, but in reviewing this thread I may have not made myself clear about those 2 situations--in both cases HPD probably knew at the time that the pistol wasn't properly registered to the person who sold it to me (they do check registrations on the computer when you apply).  They issued the permit anyway and I brought the firearms to them, at which time they then confiscated the pistols.  AFTER they had the pistols in hand, they then called the seller and I was not privy to what transpired afterwards.  So again, if the firearm is NOT properly registered to the seller, I believe HPD will make you jump through the hoops, bring the firearm to them, then they'll confiscate it.

If it is a "pre-94" long gun that didn't have to be registered they will register it to you as "no previous registration" as long as it is not stolen (of course).

So, in your situation if the seller can't remember if he registered the handgun in the first place you do run a risk of having it confiscated if it wasn't properly registered.  HPD will not tell you who is the registered owner of firearm.

if you call or go in, will they tell you if a firearm is properly registered before you complete a transaction?

IDK, but I doubt they would give you any info over the phone.  My guess is that if you went in person they would want to see the actual firearm.