A group photo of the 3 Prentiss vises I own.
7" jaw Prentiss 23, 5-1/4" jaw Prentiss 21, and 3-5/8" jaw Prentiss 51
The 4th vise is a 5" jaw Columbian 505 that is normally the lone vise on the cart.
Prentiss 21 repair thread
http://www.garagejournal.com/forum/showthread.php?t=226108...