Thank you all for the kind compliments on this rifle. It has some flaws, but I am generally please with how it came out.
Medic 302 -
I use gravers to excavate a recess in the barrel steel about 0.030 inches deep and the shape of the inlay. The bottom surface and edges of the recess are prepared (also with a graver) to provide undercuts for the gold to extrude into thereby providing permanent mechanical retention. Once the recess is prepared, I roll out a piece of 24 karat gold 0.020 inches thick and cut out a piece that just fits in the recess. With the gold piece installed, I have a maker's mark stamp that I made and that is used to compress the gold firmly into the recess and emboss the surface with the design. This last step can be done with a hammer, but I do it in a mechanical press because it affords me more control.