Saw a CL ad with pics (pic 1 &2), advertising a huge vise.
Knew immediately from the pics it was an unmarked double swivel Prentiss 22, with weight around 168 pounds with 6 inch jaws.
Seller turned out to be someone I knew years ago, so he was able to fill me in that he bought it a year ago from a machinist who lived on my end of town when I was growing up.
We actually had worked out the price for vise over phone, with one price if the pin that allows upper swivel, was stuck or able to be pulled out. (It was stuck).
Got it home and stripped it clean (pics 3,4, 5 & 6), and for first time with a Prentiss 22, was able to get vise nut and the pin that holds the nut in place extracted, which made it easy to punch out the pin from below on upper swivel.
Now have finished triplets of the Prentiss 22, with one fully marked with maker information in the castings, while the other two (including this one), have no markings at all.
Mike