Some of the MacFormat, (UK mag), cover disks from the 1990's had System software updates on them, mainly for System 7. The two that come to mind are the 7.5.5 update and also that one, rare, CD that has a copy of System 7.5.3 on it.

I've got the majority of ones from about 1995 to 1998 - they also contain loads of useful freeware, shareware, browsers etc. All stuff that can now be gotten online with some hunting, but it's much easier if you have it already!