I finally broke down and got myself a digital one, so L'il Brassy is up for grabs, if anyone is still caliper-less. *** Update: it's taken now *** Like this, but 3.5 inch max. Which is all you need, really, unless you collect giant hockey pucks. Of course you'll want the millimeter side rather than the inches side.
All done here, now. For those still looking, I will suggest you get a digital set like I just did. Cost me around ten bucks. I know you can spend a lot more on them, but this ten-dollar digital caliper (Made in China, of course, and bought from there if I remember correctly) is more than adequate to the task. I had a hard time reading that little brass one, but it did have a sort of vintage charm to it.
No kidding I just placed an lrder with wizard coin and had finalized it when I saw i needed a pair. Omg unbelievible. Right place right time.....middle of the night lol.