The Shetack engineers chart

[olderdan]

I have used one of these for longer than I care to remember, this is a second edition from 1938 bought from a boot sale. I do not know if anything like this is sold these days but it should be as it is virtually a Zues book in your pocket and very handy when working out of the workshop. If you see one don't pass it up.
BTW I totally agree with Marv that everything should be identified by size and not some reference code.