Thank you all for the comments and interest,
I made the plate from fine silver, which chisels very easily but you have to be careful to preserve the crisp edges. I cast it in 3 parts because the large plate was beyond the capacity of my small set up. I carved models from green carving wax and then used the Delft clay casting method. It essentially is sand casting using clay. I then cleaned up the edges with needle and escapement files, and a jeweler's saw. Next, I glued the pieces to wood with Elmer's wood glue to mount them in my engraving ball, and chiseled in the detail. I used round-bottomed and flat die sinker's chisels with a chasing hammer. I also ground large and small round-bottomed, a tiny flat, and 90 degree square gravers for my Lindsay Airgraver. I more or less, used the tools like wood chisels. I then fitted the 3 pieces together and soldered them with low-temp silver solder. All the joints are hidden in the design. For smoothing and polishing, I mounted diamond burrs and small stones normally used in a Dremel, in a needle file handle. Using mineral oil as a lubricant, I rubbed the metal smooth with the burrs and stones. Finally, I made different sized pencil sticks, and dipped them in oil, then pumice stone, and rubbed the metal. I repeated that process using rottenstone. After inletting and finishing the gun, I will polish the side plate with oil and aluminum oxide powder. It was a challenge to say the least but a lot of fun, and I learned a great deal. Now I need to make the wrist escutcheon. That will be fun. The rest of the mounts on the gun will be engraved steel.
dave