Thanks to all who answered, and especially JeffB. The manual he referenced
was two years newer than mine (which I did try to use) and much more clearly
showed the adjustment locations. Mine said "readjust stop screws" which no
further references.

I didn't intend for this to be a discussion as to whether the stops were
used for calibration or as movement limiters. In my case, limitation was my
goal. I use one of Ed's fine tools for calibration. (No connection.)

Again, thanks to all.

TinWoodsmn