I recently bought a turtable with a SME 3009 tonearm and the rubber parts were no longe able to support the outrigger counter-weights, the back endsection just tristed around. I did some research and found that SME will sell these direct to me (or you). I also came across a couple substites for the original "elastic bushings" as SME lists them. Online you can find a couple places that tell how to replace these, it is SME "sheet 25" that details this job.
Seem to me that the original SME design must have used these compliant bushings for a reason, perhaps to mechanically isolate the heavy counterweights from the lightweight tonearm. So using a solid replacment would seem to change this design significantly.
When I twisted the rear section completely off the main tube I found that the forward longer section was in pretty good shape, but the smaller rear section was deformed and appeared rotted away. I founs a pneumatics repair shop that had a huge assortment of "O" rings and bought a couple that seemed to have the proper ID for the center rod and O.D. to fit inside the extention tube.
I cleaned the original forward piece with some alcohol, cleand the inside of the extention, and th rearmost part of the main tube (hard to get around the central rod, so go easy here!) I used superglue per the SME instruction with the "o" ring at the end of the central rod replacing the rear rubber piece. I let it set for a n hour then used superglue to put the extention on per the SME sheet. The next day I put the counter weights and outrigger on and It works fine!
Total cost $2.18 for the O rings.