AIRBRUSHART. I have a question... Back in my hot rod days in the '60's, we made custom engine gage panels with a process called "engine turning". A round, slightly gritty object similar to a pencil eraser was put in a drill press and rotated briefly against a polished surface causing what looks like what I see in your 'pics. I know that you make a living doing this and I am not asking you to divulge any trade secrets, but is this the basic idea for "jeweling"? Thanks.
I'm also from the "60's" and raced on the streets as well as Westhampton, NY national & Islip drag strips, and yes its done the same way as gauge panels, only difference is I use a machinist drill press vise and have found that a quarter turn on my vise positions it for the next jewel, and you are correct we did call it engine turning. I don't make a living doing this, just like to play around and make my stuff a little different. A couple of things if you want to give it a try, the surface you plan to jewle must be polished to a high luster, next I use vale grinding compound 120 grit, wire wheels which I put heat shrink on so they don't flay out, or I use cratex wheels in a holder, these work good on a flat surface, this was my first rounded surface so the patterns are different than the jeweling on the LC9 & the S&W 629 hammer & trigger. In the 60's on flat panels I remember using 320 grit wet/dry sandpaper on the end of a dowel rod, do remember using valve grinding compound back then as well. As a matter of fact I still have more than 3/4 of a can of the same stuff that I use now.