Offered are No. 4 Standard Jaw Hooks for securing and registering photomechanical engravings on PMC Warnock Diagonal Block Bases. Bevel at 20 degrees. These hooks are designed for thin-lipped style bases and will not fit the later thick-lipped bases. Patent on hooks is Dec 11, 06 / Oct 31, 11. Manufacturer is Printing Machinery Co. They are used but functional.
Also available are as new hooks, keys, key bits, for honeycomb bases.
