Geometric Threading Head - 5/16" K-Grind type, w/ 1/4-20 inserts

Description

Geometric Threading Head. Geometric Tool Co, New Haven, CT. Patent #1639719
This is fully functional - collar locks and releases, and the release tab lets you remove the chasers easily. Inserts still click into place. Some tarnish but pretty good for over 50 years old (I'm guessing).
3/4" OD shaft on the back. 4" length overall.
Comes with just 1 set of inserts which are in good shape (no visible damage) - for 1/4-20 threads.
Very cool quality old tool ready to do more work. Came from an old machine shop here in CT that closed.
Inserts/Chasers are 5/16" K-grind style. I don't have any more, but they're available on ebay like here:
https://www.ebay.com/itm/333309284470?hash=item4d9ac81076:g:VfEAAOSw4lldZbVH
I'll answer any questions you have if I can.
Thanks for looking!