Here's one currently on Ebay for about $105 shipped:
https://www.ebay.com/itm/Brown-Shar...867393?hash=item521a423f01:g:aHEAAOSwowdcmtva
It has inch and metric, which is nice. Might be a little tall, though; I only have a 12x24 lathe and a smaller mill.
By the way, I read 9.201"/233.46mm, which aren't exactly the same: 9.201"=233.71mm, and 233.46mm=9.191". I suppose I could be reading it wrong, and it's not easy to really see it. I could see maybe reading a few marks in either direction on both scales. Just thought I'd ask what others saw.
View attachment 291895
Most of the other ones currently available on Ebay seem to all be missing the scribe and/or the scribe holder. A scribe is $50!
The picture is good, but not quite 'read the vernier' good, on a laptop anyway. Certain those are button heads, can't imagine a maker going to the trouble providing both without means to calibrate.
Despite age I prefer verniers, always have, but none are 25 division scales. Astigmatism seems to benefit reading a vernier accurately - if you continue regular use. Eyes are muscles that require exercise.
Most measurements jump right into perfect alignment. Certain scale positions take some investigation figuring out a dimension, when 2, 3, or 4 vie for attention.
Instead of fixating on which line up, look for what does not. . .look to right for lowest increment off by 1 [to the right of], and same to left. It seems always to be 2 divisions, so correct measure is now bracketed, oddly enough somewhere [lol] halfway between. The correct reading will now be easier to discern.
Depending how you're equipped, calibration at home can be very acceptable, even with dual scales. Must have is a proper reference plane; granite plate best, at least a machine table. I start with a substantial size gauge block, 1-2-3/ 4-5-6, angle plate; something of accurately known height. Dont have any? Have 1" round stock? Center drill both ends, relieve one end so contact is outer rim of cylinder, maybe 1/8" wide. Face off both ends, retaining center drills and relief. Check with a micrometer. Size immaterial, uhh 5.478 something who cares. Felt tip mark that on side, preserve that with clear adhesive tape.
Take a reading,
using the fine adjust. Come to think of it, that's a plus with verniers, few digital gauges have them. Hmm, it's off.
OK, time to set the scale for that touch-off, imperial and mm. Loosen the screws, be sure everything clean underneath, re-attach with screws barely touching plate; movable but not on its own.
I clip it with a wood clothes pin. Now, with a small wood or plastic stick tap it into position [correct reading] and snug the screws up. Paint a little smudge where screw and plate meet. This is NOT a place for thread locking compounds! Finger nail polish is perfect. Don't tell me you haven't a bottle in the tool box yet. Any color but clear. Enamel paint works too, but I'd rather shake a little bottle than a gallon of real paint which is harder to remove.
Replace scriber with a .0001 or better test indicator on, and zero without displacing the vernier. Now, stage other known blocks via the slide AND fine adjust mechanism, leaving height gauge in place. If initial set is correct, you'll register complying vernier dimensions and indicator reading. The only difference will be if you came up [or down] for the setting and did opposite in subsequent readings. That's likely indicator back lash.
Once or two tries, you'll be able to say "I calibrated it".
