Wulf.
Here is the only photo of my machine I have handy right now. It is like a stock duplicator. The head runs on the two rails. You can find some like this on the web under carving machines.
The cutter head is a router for trimming tile and takes a 1/4" bit. I have several different bits for it and matching styluses. I made it my self. I learned when I made it that there is an esier way to do it than this. That is another subject. It cost me about $500.00 to make this. The most expensive parts were the radial bearings and precision shafts. There is no shortcut to eliminate them. This works great for ram rod grooves and barrel inlets. The table is 8' long. It can cut a 44" barrel channel. It is very accurate.