Even though I live in the heart of Confederate collecting am at a loss to give a good reference. I would take the pistol to a good Civil War show make the rounds of tables see what the dealers say. And don't take the first offer.
One problem with Confederate relics is so many have been counterfeited it makes it hard to determine the value of legitimate. However your pistol is so unique it's not likely it was faked. Perhaps half claiming Confederate use are fakes. Got myself in trouble at Portobello road antique market in London. Picked up a Sword, fairly good copy of Ames CW model. Fellow gave me the sell before I could say anything. When he finished in my best Virginia accent told him it was a &@3* fake made in Spain. He did not take it well.
Here is a link to shows. Only one I know personally is the November Richmond show
http://www.confederateplanet.com/upc...ria-shows.html
Bill