Watch out for the scare quotes though - it actually did give me the opportunity to check: Finder 1.0 shipped with System file .97, and Finder 1.1 shipped with System file 1.1g - and it looks like “System Software 1.0” actually refers to Finder 5.2/System file 3.1!

https://en.wikipedia.org/wiki/Classic_Mac_OS#System_1,_2,_3,...