Dy-Mac rethreading tool used by Chrysler mechanics during 50's
 

I'm looking for info on the Dy-Mac rethreading tool that was used by Chrysler mechanics in the 50's to rethread truck and bus axels. My grandfather, Eugene Dyson, was the "Dy" in Dy-Mac and designed and manufactured the tool. My uncle says all Chrysler dealerships of a certain size were required to carry the tool. It was a cast iron ring with 5 adjustable riders, 1 adjustable cutter, and 2 handles that were positioned radially around the ring. I can post a photo of it when I get to another computer. I'm working with the New Britain Industrial Museum in New Britain, CT on a display and looking for more info on its use and wondering if there is one still in existence that we could get better photos of or acquire. Thanks!

Picture of Dy-Mac rethreading tool
 

Retreading was for truck and bus rear housings and other machine parts. Here's an old sales brochure with a b&w photo of the tool. http://greatblue.com/nbim/dy-mac-sales-letter.jpg