was dated 1940. It is so old that it shows line drawings of machinists with no safety glasses. OSHA or no OSHA, I'm sure that's a bad idea.

My experience with stuff built in '40s was that it was mostly way over-built. I'll take their word for recommended thread depths.

Did you manage to run down a set of thread chasers? Some places call them thread restorers. The set I have isn't much more than the size of a nut for the respective bolt. Seems they're more elaborate these days and also more money.