Getting hot and heavy into the 3rd generation autos and have noticed that some of the same model number autos have their labeling either as an "impression" into the slide or it is "lasered" on. I would assume that the laser work came later, but I have been unable to verify this. What gives?
The earlier guns had the trademarks rollmarked on, and you are correct that the later models had laser etching done. I don't have any with the laser etching though, I find the rollmarks look a little better.