Rex B wrote:
....
I'd be happy to make any measurements or comparisons that would help.

Thanks, I think that I'm all set. I've been looking around and I'm
pretty confident about it. I was kinda in the dark about the number of
teeth on the gear. Scott Logan (I think it was) in a Yahoo post
explained it: the number of gear teeth divided by the screw tpi gives
the highest number on the dial. E.g., 16 / 8 = 2, the dial has "1" &
"2". The number gives the fractional pitch possible. E.g., 1/2 for 2,
1/4 for 4.

Bob