I guess it all comes down to what you mean by "pretty good shape".
Does it "apparently" have a functioning lock or is the lock seized up"? In other words, is it a wall hanger or with a little/lot of work could it be made functional? Wallhangers like this are not uncommon in the U.S., I believe. Its been a while since I priced any, but I vaguely remember wallhangers being in the $500 to $800 range in U.S. shops.
Since you are a dealer????, of course you know not to fool around with it until it is examined by a qualified gunsmith.
I'm impressed that it still has a bayonet. Does it also have an original ramrod?
What condition is the stock?
On the 'net, if you google "civil war message boards" or some such thing you are sure to come across some message boards where the members have tremendous expertise in these matters.
