OK, some good news: I was able to locate more tips from : "XML-RPC with ZClasses" http://www.zope.org/Members/teyc/pipermailXMLRPCWodes/ So I have implemented the one major change: 1. Fix the import error to support "encode string"-by adding from base64 import encodestring and I went back and re-adjusted that block to the way Amos had it because per my earlier email, I had already fixed the subclassing error. But it still isn't working yet!