Re:
i rebuilt a magnum earlier this year- seals and bushings were in good condition so i only needed to replace the elastomers and bumpers. That thread is here:
viewtopic.php?f=6&t=361369
the elastomers were purchased from bikerecyclery which is also in the states- i'm not sure how the price is relative to suspensionforkparts.something after shipping, but the initial cost for the kit i bought was a bit less than half the kit from the suspensioPartsGuyThing so i assume it's something people might actually be able to afford.
The kit i bought is here:
http://www.bikerecyclery.com/vintage-ma ... -r-medium/
looks like there's still a couple left... basically, elastomers and guides from the sx/spyder fit in the magnum legs and if you get around 6" of them they are a suitable replacement in the magnum/comp/3/4. They won't work in the 1/2/sport though, those were a little different.
There's other kits that will work there too...whatever looks like it has 6" of elastomer. They also had elastomers for the quadra which are very similar to the elastomers used in the comp.
If you are trying to find urethane rod stock in the right durometer i can't say what will work. Something in the 40-60 range is what i've seen others recommend. I've ordered some 50a urethane rod in almost the same dimensions as the elasto used in the mani 1/2/sport and i'll probably post how that works (i swear all the posts about using urethane rod stock in early manitous end at "i'll keep you updated!") when that rebuild is finished. I found that on ebay- the seller was like an outlet for a urethane manufacturer that was selling over-runs and "drops" and one just so happened to be the right size.
for the bottom out bumpers i used some 60a " PUR hollow round rod" purchased from Amazon cut to about 1-1/2 inch. That's not the original length... but it's what i needed to stop the travel at around 2" since i was using shorter than normal top out bumpers and a longer elasto stack (because of the coil spring).
For top out bumpers i used the top outs form a couple wasted judy forks. There's no shortage of those...
Fork works pretty good... although i never use it since i never rid the bike they're on.