Try the Blue Book of Gun Values
You will need to have it examined by a competent gunsmith to be sure.
Chances are that your forehand double barrel was made by Crescent Firearms Co.These shotguns will bring between 50-150 dollars depending on condition,and a good set of bores.
Beginning of the barrel to end of barrel.
Turn of the century, utility hand gun.
Can you email me with the complete markings on the gun, and possibly digital photos? The patent dates are in the same general range as Forehand & Wadsworth, but not exactly. sales@countrygunsmith.net
Yes, that is a fairly common barrel length.
Frame, barrel and cylinder
No one revolver, no one size, no one answer.
Can't be answered without a DETAILED description of ALL markings, barrel length, sights, stock material, box, papers, accessories, history, finish, overall condition, etc..
A bullet that has left the barrel has marks left from its travel down the barrel.
A rifle that has barrel removed- not likely. Revolver that has barrel removed- VERY likely.
It should be marked on the barrel.