Older Manitous like that are pretty easy to disassemble, ddac. The key to opening one up is a 6mm? (I believe- - I'd have to check back in my haphazard pile of plans) stub of an allen wrench on about an 18"-long T-handle (easy to fabricate). Or see if you can borrow the one your LBS has. This T-wrench is what lets you hold the top of the inside rods so that you can loosen the bolts on the bottom of the sliders. Once those bolts are out the sliders with separate from the stanchions.
Then it's a matter, as Svr says, of disassembling and going over the damper cartridge o-rings and seals and replacing all of the culprit and suspect rubber.
I'll try to track down some disassembly instructions for you - - either of the Manitou or of a very similar-model RST (who did most of the contract-manufacturing for those Manitous). In some ways, yes, it may be time to think about a new fork; BUT - - this might be just the time to learn, as you say. You've got one that is fairly user-friendly to service yourself; a good opportunity to expand your knowledge base.
Originally Posted by Mark Twain
"Don't argue with stupid people; they will drag you down to their level and then beat you with experience."
Last edited by dminor; 09-10-09 at 11:52 AM.