I too have modern copy of the Machinery Handbook — was referred to as “the bible” in the 1960’s where I worked, there was a copy in Inspection and a workshop copy. I use mine occasionally but the Zeus book is my go to source for general info, also have the Black book a recent acquisition — maybe 8/10 years ago?
The copy of MHB was on offer from an American company I bought specialist goods/tools from and bought it only because it was very inexpensive at the time as a”handy to have ”
Some posts back there was a reference to British Standards appearing, prior to that and I understand the forerunner to standardisation was the Newall table of limits and fits from early 1900’s and it was adopted by much of industry before the more comprehensive BS were issued. I have a copy of it somewhere.
I spent a few weeks at Newall’s in 1966 and was told they made sheep shearing equipment and exported to Australia NZ etc thus introduced the standard to ensure parts shipped there would always fit.
Found this which is interesting https://www.newall.org.uk/files/2017/03/A-Matter-of-Fact.compressed.pdf
John