...have turned up at this dealer,...
If I'm reading your post correctly, you first saw these guns at the dealer's shop, and then used your "detective skills" to track down the owner/seller. Seems to me that you owe the dealer at least a heads-up that you would like to buy the guns, even if he does not get the consignment (assuming that it is a consignment sale). Let the dealer call the seller and tell him/her that he has an actual buyer waiting with cash for these guns, for an immediate sale. Reach a fair arrangement with the dealer and everybody wins. If your dealer can't get the consignment, all bets are off. If you can't muster enough cash to do the deal now, let the dealer buy gun 1, or arrange some sort of payment plan with him that keeps him whole on the carrying costs of the inventory.
