This is not for sale but to maybe get an idea.
My CVA Mountain Stalker rifle, originally had a 26 inch barrel.
I found a local machine shop that I hired to cut the barrel down to 19 inches and recrowned it. They also cut two new dovetail slots, 1 for the front sight and the other underneath the barrel for the ramrod thimble. They did an excellent job for only 150 bucks.
Traditions TN full stock, 1/38 twist excellent shape .50 24"barrel $525 plus shipping (ya I know it was less last time but nobody bought it and Now I Think Its Worth More). Try an find a full stock .50 in this shape. Not listed recently but everything's for sale.