With a federal Curio and Relics license, eligible firearms can be shipped directly to your home (state and local laws permitting). Eligible are any firearms specifically on the C&R list plus ANY firearm manufactured over 50 years ago. "The principal advantage of a collector’s license is that a licensed collector can acquire curios or relics in interstate commerce."
It's only $30 for three years, and you get some useful manuals. You also occasionally get notices from BATFE regarding major local firearm thefts and issues.
Brownell's and some other dealers give you a discount.
On the other hand, you must keep some simple records and you pretty much give BATFE carte blanche regarding your premises.