Hello Ian,
Welcome to the Forum from another Wood, although as far as I know, we are not related
I too live in North Yorkshire (Thirsk) and have a few years on you at 79. I do have to admit to being an incomer to the county with my origins in S London until we got bombed out in 1941 and I finally settled up here over 30 years ago.
My main interest is in machine tools and restoration work. A recent commission was a full rebuild of an original Norton screw cutting gearbox for a 12 inch swing American Hendey lathe built in 1902 which had damage to every one of the 15 gears, all of which I re-cut in either new material or from cut down originals where it was appropriate. I have a pretty well equipped workshop in which to do these things
I have had one of those little circular charts for many years and used it a lot in past years, but sadly the need for magnification to read it is the order of the day now and it lives in the back of the measuring department cupboard.
Regards
Brian