The caliber is of course a small game caliber. Also the double trigger was very common on rifles long ago. As for the gun maker, there were so many small gun makers years ago, it is hard to keep track of them all. Many gun makers might make a limited number of rifle for clients. Many of them have some expert craftsmanship to them. I would guess this was not a mass produced rifle.

As to the value, the caliber is well sought after. If the rifle is in good condition, the bore is good and not rusted, and the quality of the stock and fit of the hardware to the wood is good.. all of this sets the price. Without a close examination of the rifle it would be impossible to even guess what the rifle is worth. Almost any traditional muzzleloader is worth money. They value from$100 - $2000++++ . It all depends on the rifle and the quality of the gun and components.

Being something handed down, I would say it was priceless.