My apologies for the delays in getting these up, I was away from work and my computer for most of this past week on account of my fiancée being in from out of state. Anywho, people wanted to see DMG pics, so here we are:
This first pic is of cases that have had successful engravings on them. The color is a little off because this was shot under incandescent light. Now, these are cases which were already clean and looking nice to begin with. Cases which are badly UV damaged will have much less desirable results, and can get strange mottling and such, as you can see here:
Retrobrite-treated cases will have an identical problem, since engraving them will cut down into lower layers of the plastic which have not been touched by the reaction, so the mottling will reappear.
It should also be obvious that DMG case backs, as well as the ASM reproductions, are not great candidates for engraving to begin with, as the characteristic "ridges" molded into the backs take away almost all the usable room on the backside. Kitsch's cases have a distinct advantage in that regard, being much more flat and open on the backside.