That's the thing with the Proflex/Girvin suspension, it's pretty unique to those bikes and those bikes alone.
From my experience you can...
1. use Land Rover bushes which are cheap enough to find,
2. get new elastomers from suspensionforkparts.net (they have a current listing on Ebay) which are pricey but should last for years and year
3. or try and find/fit an ODS system (if that is even possible?), depends on your model of fork I think.
4. Modify/machine something to allow you to fit a different shock. I got an, adapter for the rear of my Proflex that someone had made by "man with lathe" and allowed me to fit a modern Fox shock, I've also seen pictures on this forum of someone who made bushes etc and fitted a modern air shock to a set of Girvin forks, so it is possible if you have the time/skill/money.
Have a look on the Proflex idriders forum and see what you can find on there... http://idriders.com/proflex/smf/index.php?board=1.0