Hi,
The pistols were probably by John Hawkins (not Hawken) although the barrels are marked "RW" likely for Richard Wilson. The lock is from the late 1740s so they must have been made near the end of Hawkins' career. I think some repros of the pistols were made in Europe some years ago and sold in the US by the U. S. Historical Society and sold in a case. The rifle shop sells castings for the butt cap, trigger guard, side plate, and thumb plate that are very close to the originals. It is their series 589 butt cap and end cap, and their series 615 trigger guard, side plate, and wrist plate. However, I suspect they are all cast either in brass or steel. You might be able to have them cast is sterling silver but it could take a while.
dave