I have a few of the 5200 installer CDs and from what I remember they contain System 7.5.1 and will work on 68K machines. I seem to remember once using one of the disks to install 7.5 on an LC475 and it worked fine... However, my discs may be different as the simply say "Macintosh Performa" on the front and list models 5200, 5300 and 6200. I seem to remember they have ClarisWorks 3.0 on them as well.

As far as I know, System 7.6 was the first version that used native PPC code but someone please correct me if I'm wrong.