Gang,
Post Script-- I just got an MSC catalog in the mail today. It contained, of all things, Diamond tipped grinder wheel dressing tools. Todays cost for a 1/5 ct x 3/8" shank diameter tool is $25.97 + shipping. I think this may partially explain why the Craftsman version disappeared in 1955; too expensive for the average DIY shopper of the day (especially when the time tested alternative cost less than 1/4 the price).