Apparently PSE3 can no longer be loaded on my new Mac OSX Yosemite machine which also has PSE13.

My old Epson R210 photo printer formats for printing better with PSE3 and that's why I would prefer to keep it if I can but Yosemite just would not install it.

Any suggestions?

The Epson R210 is about 8 years old and still works perfectly.