The cost of a C&R license is $30.00 for 3 years. Completing the application form isn’t that much different than the 4473 you complete when you purchase a firearm, basically the same information just a different layout.
The purpose of Collector of Curio and Relics License according to the ATF:
“The principal advantage of a Collector's License is that a collector can acquire curios or relics in interstate commerce. Although a licensed collector may acquire and dispose of curios or relics at any location, dispositions to nonlicensees must generally be made to residents of the same State in which the collector is licensed. Further, A LICENSED COLLECTOR IS NOT AUTHORIZED TO ENGAGE IN BUSINESS AS A DEALER IN ANY FIREARMS, INCLUDING CURIOS OR RELICS. A FEDERAL FIREARMS DEALER'S LICENSE IS REQUIRED FOR THIS ACTIVITY. The term “engaged in business” as applied to a dealer in firearms refers, in part, to a person who devotes time, attention, and labor to engaging in such activity as a regular course of trade or business with the principal objective of livelihood and profit. Therefore, any person intending to “engage in the business” of selling firearms, including firearms defined by ATF as Curios or Relics, must first obtain a dealer’s license. For example, if a collector acquires curios or relics for the purpose of sale rather than to enhance a collection, the collector would have to be licensed as a dealer in firearms under the GCA. The sole intent and purpose of the collector’s license is to enable a firearms collector to obtain curio or relic firearms from outside his or her State of residence.”
This does not mean you cannot sell some of your C&R firearms, just don't sell so many that you could be making a living at it.
What is considered a Curio or Relic according to ATF:
Firearms automatically attain curio or relic (C&R) status when they are 50 years old. Any firearm that is at least 50 years old, and in its original configuration, would qualify as a C&R firearm. It is not necessary for such firearms to be listed in ATF’s C&R list. However, if your C&R item is regulated under the National Firearms Act (NFA) and you desire removal from the provisions of the NFA, you must submit the firearm to the Firearms Technology Branch for evaluation and a formal classification.
The Firearms Curios or Relics List is located at HERE of particular interest are these 3 entries:
1. All Original military bolt action and semiautomatic rifles mfd. between 1899 and 1946.
2. All properly marked and identified semiautomatic pistols and revolvers used by, or mfd. for, any military organization prior to 1946.
3. All shotguns, properly marked and identified as mfd. for any military organization prior to 1946 and in their original military configuration only.
Sorry Rick, no loopholes to owning Thompsons with this. It may be considered a Curio and Relic BUT it still falls under the NFA of 1934 if it is full auto.
Possible drawbacks of a C&R license- You must keep a “bound book” accounting for your C&R acquisitions and disposals. ATF can come to your home and inspect the “bound book” for your C&R collection.