I'll give you $100 sight unseen right now!
To be truthfull, I highly recommend www.GunBroker.com
I sold my father's entire collection there by myself. I started every auction at a penny and I never had a reserve. If you truly have an original 1847 Walker and you wish to sell it for the highest price possible, I recommend a 14 day auction starting at a penny with no reserve.
Many people get nervous that they will only get a penny for the gun. This is unfounded. Thousands upon thousands of collectors scour GunBroker. Be sure to take many, many pictures with a quality camera. And give a full written description. If it's truly an original then it's an antique and no FFL or C&R license is required by the buyer. Just a photo copy with their payment of a State issued picture ID that they are 21 years of age and a letter stating they are able to purchase the gun legally.
With a no reserve auction, you get people bidding. Everyone gets interested because they are simply bidding against each other instead of against an unknown reserve. They see the current bid and decide they will be higher.
When I sold my dad's guns, I sold most of them for OVER the 2007 Blue Book of Gun Values prices. A particular Colt .380 sold for $3125 when the Blue Book said just $1000. What does that tell you? The fair market will set the price for you. There can be no complaint when it sells because with no reserve, it will sell for exactly what is was worth...to a particular buyer.
And the really nice thing is that you get the money instead of splitting too much with a gun shop or live auction house. Yeah, GunBroker takes their cut, but it's a small cut compared to everyone else out there.