The 4473 has always hacked me off. It is essentially gun registration, they just make the dealers do the work. The ATF can come inspect a dealer's paperwork unannounced at any time. They had better have a 4473 for every gun that came from the distributor and is no longer in the store. They now know what you have.
The only thing they can track is form the manufacturer to a distributor to a dealer and then the first retail sale.
To even do this they need the make and serial number.
If the gun goes back to another FFL, or is sold privately, the trail ends.
If the FFL goes out of business 4473s less than 20 years old go to BATFE.
The dealers bound book goes to BATFE whenever the FFL is terminated.
BATFE is prohibited from computerizing the records they have.
they have top keep them as paper and search through them by hand.