When typography terms are debated again, I like to check very old sources and I know good ones in German, but are there such books which can be considered a “standard” in English? I mean book which are like 100, 200 or more years old and describe printing/typography terms and are hopefully also available as scans. 

(Literally) a case in point: I saw some slightly varying explanations about the origins of the words uppercase and lowercase this week and that’s a typical case where I would like to check old sources to learn more about the traditional understanding and origin of such terms. 

Still searching for a source for you, but I always understood the terms as deriving from the drawer positions on a traditional typecase cabinet—uppercase on the upper tier, lowercase on the bottom.

I assume you have now found an authoritative source?

 

Yes, like this one: https://archive.org/details/printersdictiona00stewrich

Still happy to learn about more sources like this. 

Joseph Moxon's 'Mechanick Exercises', is a must-read.