First time I've heard of an offer below face value for currency. Sounds like a dealer I wouldn't do much business with.
Looking at a couple places online, I'm thinking you might do better with a real auction house. Great find!
http://www.historyforsale.com/html/d...art=1&signer=L
one of the guys here seems like a good contact.
http://www.charleslindbergh.com/cgi-...c;f=1;t=000675
Persoanlly I'd consider keeping the items together. Or at least the items less the lindbergh auto. As a group especially including the lindbergh they tell a bigger story, and probably have more value both historic and financially.
Some info on Lindbergh in WWII here
http://www.charleslindbergh.com/wwii/
Steve B