When my latest acquisition came in the mail last night, a Griffon 60 carbo magnetic, the more i looked at the grind the more interested I got: I began to suspect it was double hollow ground, or 'double concave king barber' on the old Griffon ads.

Its 7/8 with minimal wear, doesn't say 'Rex Tonsor' anywhere on it, but naked eye and feel were indicating an almost imperceptable 2nd grind.

Well, I just looked at it under shop microscope at work with mag turned all the way down, and, lo and behold, with the light angled just right that 2nd hollow jumps out plain as day. It goes to about 1/4 blade width. The transition is so smooth my eyes doubt what i'm seeing unmagnified but its definitely there.

Now I have an original ad from 1908 that I'm going to frame, and both types of model 60 just like in the ad.