There is a WTB on Swapping and Selling currently and I fear I may have strayed too far into discussion trying to help the OP with his search, so I’m repeating it here in case that post is considered out of place. I’d like this info to be available in the future.
To add to your store of knowledge, these measures were marketed as Pacific, then by Bair, then again by Pacific. The earliest Pacific ones were made prior to WW II had a black painted cast iron body and a brass tube powder reservoir. The later models went to the blue paint and a plastic tube. The latest ones replaced the screw clamp with a plate arrangement that screwed to your bench to hold the measure. You will find rotors with different lengths and styles of knurling and even some wartime rotors made of steel when brass was in short supply. Don’t let that bother you though, AFAIK, all of the Pacific and Bair rotors work in all of these measures.
There was a two page write up of these measures on the late, lamented Project 55, which covered the Lyman 55 and several comparable measures but so far the folks at ARTCA have been unable to resurrect it. I have a saved copy of the pages on my laptop, but it’s a scanned copy of a folded hard copy and pretty unreadable.
Froggie