Just to show that Tom aint chittin ya (for once), here's a picture of the gun so far. Haven't even done the front of the panels yet. I don't like trying to hold the delicate forestock in a vice so I leave it to last.
Jim, try this, rather than useing a V parting tool, I use a VERY small veiner. Here's a picture of the one I use most. It's the smallest one Phiel makes. Even though it's a palm chisel, I drive it with a mallet. Problem with a V parting tool (at least for me) is that unless your depth is perfevtly consistent, the width of the line will vary and appear wavy. The veiner has parralel sides so once you reach enough depth to ride on the vertical sides, variations will not result in a varied line width. After cutting my design, I then go back and vary the line where I want to with a small flat. Here's an early picture of the carving on this gun, all incised. I did use a Vparting tool for the cross hatching for no particular reason, just seemed like the thing to do.
Tim, I did a few practice plates when I was learning to use a 120 deg graver but otherwise, I never practice. I have time just lack the ambition.