tobnpr, yes, I've read that letter, which only specifies the acquisition of firearms, it says nothing about what to do with a disposition. That omission doesn't free you from following the law as I quoted earlier. If you want another reference, let's look at the Code of Federal Regulations, which is referred to a number of times in the actual law.
27 CFR 178.125
(f) Firearms receipt and disposition by
licensed collectors. Each licensed col-
lector shall enter into a record each re-
ceipt and disposition of firearms curios
or relics. The record required by this
Again, this couldn't be simpler. Each receipt and disposition.
I think you're operating under the impression that the license is somehow tied to the specific firearms. It's not. With any other FFL, it's tied to the business, so only firearms that go through the business need to be recorded. A C&R is different, in that it's tied to a person. There's no difference between what you owned previously or what you acquired after you got your license because the individual firearms don't matter. What matters is the transaction, and each and every transaction of qualifying firearms must be logged.