States and police much rather you have concealed carry, I read somewhere it was preferred cause it's less "scary" so if we get open carry we will probably get concealed.
One could also argue that they physically couldn't conceal cause most guns were too large not that they weren't allowed. Though I am not an historian. It's there no evidence of concealed carry? I find it hard to believe.
What the state or police prefer has no bearing to constitutional rights. They can ask the citizenry to conceal vice open but they can't make a law, policy, or edict that forces conceal over open even if it "scares" other people. Assuming open carry was constitutional protected. That plays into the hands of the anti 2A people. "You shouldn't own a black assault military rifle because it is so scary". Also that type of attitude of the Police pushing the "preference" feeds their ego of "my word is law". If you don't follow the request, then you are breaking the law and subject to arrest or citation. For example (this happens a lot) You are not detain, arrested, or have a suspicion of wrong doing but I want you to hand over your ID so I can check for warrants. Failure to give me your ID will result in your arrest.
I don't think the founders, when writing the 2nd Amendment, had arguments about the concealability of guns and the size of the firearms. I really doubt (like you I'm not a historian) that founders where complaining about how bulky their firearms are and wished they were smaller so that it was easier to hide. In my opinion people that were concealing guns back in the founding era were criminals. i.e. the criminal wanted to put the victim in a false sense of safety until they can ambush the victim. It is exhausting but it is amazing how heighten your awareness is when you see everybody (kids, women, old men, etc) with some type of weapon. You trust them but you are always scanning and assessing the treat when you see a firearm. "Rifles at the ready".
I also believe the founders/settlers really did not care about "hiding" the fact they had a firearm. I believe "hiding" a pistol became more in fashion when the people started to be "civilized". They wanted to give the air of "this town/city is so safe I don't need a gun" but secretly have the ability to fight back if needed. Almost what we want today. Give the appearance that everything is fine but if something hits the fan, the citizen has the ability to protect self and family. The test of time according to page 12 Young, "historical analysis is to determine whether the challenged law falls within the scope of the right as it was understood during the founding era." So just because concealing a weapon became a norm in the preceding decades after the founding, it was not the norm in the "founding era".
Anyway... I don't think the argument should be if CCW or OC is protected but if "Carry" in any form and with any firearm (rifle or pistol) is protected. Then let the gun owner determine how they want to carry, open or concealed, just like in the founding era.