Ok, I've got a fun one, my C&R comes up for renewal on August 1st, I was getting it ready to send in when all this @#$% hit. Question #3 on the renewal:
"Will the requirements of State and local law that are applicable to the firearms or ammunition activity or collection of curious or relics, be met prior to the start of the business or collection activity?"
Holy crap there are a whole bunch of issues there. I started activity in 2013, when i THOUGHT it was legal. Now I'm not sure. I've got an M1 Garand an a really, really back Chinese SKS on my C&R.
I think that has more to do with proper license requirements for your state? for example I think this same question was on the FFL application the ATF will not grant your license unless your state requirements are in place "business address, tax # and such.