George,
How about an out of the box suggestion?
Get some tables at the Southern SxS, if they are available. Have a silent auction. Folks walk up, write down what they want to pay. If it doesn't meet your needs, don't accept the offer. No auctioneer min to pay, you'll know your costs up front. Buyer can pay any transfer fees on the modern stuff.
You could make it a no reserve silent bid. It could be really interesting.
Deep River could transfer the modern guns, or what ever dealer you use.
Give Bill K. a call. I think a lot of folks want to help.
Joe