Simple, use a piece of square stock,, 1/2,, 3/4"long or so, where milled,, ball mill to match profile,, , clamp the barrels lightly, add heat sink paste 1-2 " or so from the end of the plug/barrel, and put a new long shank bead sight in after drilling the hole in the plug when it's in place and solder with a old time large iron that you heat up with a torch and solder everything in place and block/stone flat,,, finish,,,,,done.
If you want to be real tricky,, undersized it by about 3-4 thousands,, brass shim the block tight and even on all 4 sides,, push the brass shims in a 1/4 " or so and fill the void with silver solder,,,, makes a dandy silver hourglass pattern when refinished,,,,,,
which will be last thing the,, perps,, will see just before ,,,, "THERE TIMES UP ",,,,,
