I just picked up a Gorton Tool Grinder and am in need of a 1/8" collet. From internet research, I think its a 4NS. This seems to pretty much be unavailable, short of made to order. Can anyone confirm this is the correct collet ID for the Gorton and are there any out there?

Up until now, I've been purchasing ground and sharpened cutters--to the tune of a few thousand $$ annually--any instruction manuals available? Trying to hire a local to come by and teach the gang how to run the machine, but I'd like to go over it first and get it properly cleaned and lubed.