Jerry,
Its a good idea to upgrade. We have recently replaced 2 older systems because the processors failed. Even if you can get a working processor, the system could have other problems and that processor that works is still old. It would be like trying to find an old original engine for a car thats 15 years old rather than upgrading it. Can work, but its old and may fail sooner than later.
Im in Miami, FL so there is very little that I can do from here. Sorry if this isnt the help you need. If you have any other questions, let me know.
Alex - alex@iqei.tv