Andy, yes, that is also "diamond point," though the technique on these modern examples is different from the diamond point engraving of the 16th and 17th centuries. I've done the same sort of thing with my Dremel.
There's an artist, Paul Darlington, who does stipple diamond point engraving: using a diamond-tipped stylus (no electricity) makes thousands of dots to form an image. Amazing work. For some reason the links to his site don't work anymore.
I found lots of references for Ernest Michael Dinkel and examples of his work, but nothing else on glass. Same guy that johnphillip mentions, though, based on the dates.