Trapdoor Rifles

I hate to do it but I just can't shoot my carbine with the open sights. It is a 1880, slotted screws, full butt stock kit, barrel was relined by Bob Hoyt. Barrel is 3 groove, .458".
What is a fair price for it? I know it is hard to say for certain without photos, but better than average.

Pictures would be helpful in determining a value.

That is on my list of things to do. Just farther down the list.