Back when I lived on the ,mainland, I had a C&R permit which was helpful for a lot of reasons.

Are those easily obtained here too, or is it a giant hassle like most things firearm related here?

Seeing as how the ATF has gone off the deep end lately I would avoid dealing with them as much as possible, at least until a new administration can reign them in.

It should be just as easy as before on the mainland.

But as HvyBarrels said it might not be worth dealing with them right now. It would put your name at the forefront on someones desk. You never know.

This regime is power hungry and you never know when you might be singled out to be made an example of. JMHO

It's a federal license, so the local gov't has little involvement.

If you are a collector, then the license makes sense.  It's not that expensive, and you can have your purchases sent directly to yourself, avoiding the FFL transfer fees.

If your A&D Records (Acquisition and Disposition) are in order, you won't need to fear any ATF visits.  The rules are relatively few and simple.

The biggest hassle is that we're in Hawaii where 100% registration of all firearms is required.  You'll need to spoon-feed the police department everything they need to let you register.  I needed a long gun permit, my ID, all the info on the firearm including invoice and importer identification, HOW it qualifies as a C&R firearm, and a copy of my C&R license.

If you have a page from the ATF guide that says any firearm over 50 years qualifies, then you need something to show the production year of the firearm.  Some manufacturers marked the date on the firearm, but many do not.  You'd need a certification from the manufacturer, a purchase invoice/receipt from the original buyer, or some other documentation proving its age.  On the other hand, if the firearm is specifically listed in the ATF classification listing, it's not a problem.  Just copy that page as your "proof."

https://www.atf.gov/firearms/qa/what-firearms-are-considered-be-curio-and-relic-firearms