Check out GunsAmerica website and perhaps closed auctions on Gun Broker and Auction Arms. All are internet based operations to sell firearms through dealers. These should give you an idea of what is going on now from a price stand point. Many of the guns posted on GunsAmerica's web site are a bit over priced in my opinion, but that is my opinion. Just depends on how quickly you want to sell the firearm.
Things like condition make a huge difference in value. The Colt single action 22's are excellent guns and have some collector interest. To give you and idea, post barrel length, finish, condition, serial number (with the last digits xxx'd). Do you have the original box? Does it have the extra 22WMR cylinder? It is fairly easy to give you a rough value based on the Blue Book pricing, but Colts have been increasing in value and the Blue Book price may be low. The Peacemaker Scout (G or L prefix on the serial number) is listed at $550 in new condition ($400 for 98% condition) with add ons for some limited production variations and the original box. These would be considered "retail" prices versus the price a dealer would purchase it from you.
If you are in my state, heck I might buy it from you. I like those little revolvers.