That is really deep brass wire. Do you really think it was that deep on the Oerter rifles?
One thing I saw in your video that I am going to adopt is that pair of plyers that you used to file the end of the wire the you nipped off. I have always just used my thumb or finger to file the end of the wire but that's is rough on the fingers after several hours of wire inlay. Did you buy or make the plyers?