Okay, I'm just gonna leave this here 'cause there has been so much

[Marengo]

31. C&R licensees are not required to surrender records to the BATF...

if the license lapses without renewal. That requirement is for licensees who maintain a business.

Found this reference on the ATF website:

Q: Are licensed collectors required to turn in their acquisition/disposition records to ATF if their collector’s license is not renewed or they discontinue their collecting activity?
No. The GCA requires the delivery of required records to the Government within 30 days after a firearm “business” is discontinued. A license as a collector of curios or relics does not authorize any business with respect to firearms. This is in contrast to firearm importers, manufacturers, and dealers who are licensed to engage in a firearms business. Therefore, the records required to be kept by licensed collectors under the law and regulations are not business records and are not required to be turned in to ATF when collectors’ licenses are not renewed or collecting activity under such licenses is discontinued.
[18 U.S.C. 923(g)(4), 18 U.S.C 27 CFR18 U.S.C 478.127]

http://www.nibin.gov/firearms/faq/curios-relics.html#surrender-bound-book