G'day kingchops.

I sold you that 520c, so I feel obliged to try and help here

I can't rightly remember if I trashed the files, so if you open "extensions manager" in the control panels, you might be able to re-enable file sharing.

Another (long) alternative is to find 19 mac formatted floppies and install Mac OS 7.5.3 from here:

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/System/Older_System/System_7.5_Version_7.5.3/

Glad to hear that in in spite of networking difficulties the 520c is working great.

Best of luck networking with your plus!