Check out this site:
http://klesinger.com/jbp/tgun2.html
The following is a excerpt that mentions Chance, but I strongly suggest you read the whole site, as it is good information and as far as I can tell, very accurate and well written.
The site discusses trade guns and says this about Chance:
"Seems that William Chance Son and Company of Birmingham, England got the large orders and any additional guns were gotten locally in New York and Pennsylvania from Henry and Tryon or from importers with agents here in America, handling Belgian guns.
1850
W.Chance Son & Co.,Birmingham [16]
160 with 36 inch barrels
110 with 42 inch barrels
10 with 48 inch barrels"
Your gun likely dates to about 1850. I honestly have no idea of value.
I can't imagine anyone trying to fire it, but strongly recommend against it. Damascus (twist) barrels are weak at best, and a gun that has not been well cared for could be rusted out and very dangerous.
I also caution to use a ramrod to determine if the gun is loaded. (Many old shotguns are!) If it is, you will need to pull the load, using a device called a worm. Try to find a shop in your area that specializes in antique guns; they will be able to provide more information. Meanwhile, treat the gun as if is loaded and handle with care.
Jim
