Well, I bought a automobile spray for the door rubbers preservation and restoration: did not work, sort of silicone fluid, did not soften the rubber.
I spoke yesterday with my garage mechanic, who told me that he used to "soften" rubber bands in soaking them a night long in some liquid machine washer soap (you name it : skip, tide etc. )
That is what I've done : overnight bath in plain "X.tra" detergent, water rincing then cloth drying:
Now the rubber is much softer and flexible than before and not tacky at all.
After a few spins on some abrasive paper on the edge and here it goes.
Tried it on the TT: instant speed up, no more speed variations and much quieter too.
So who's next to try it?
MicroSeiki RX1500VG + Ikeda IT407 12" tonearm / SPU classic GME mkII.
Denon HA1000 + Audiotechnica AT33EV + Shelter 501Mk2 + Denon DL103R
Neat M68 TT Ortofon SMG212 + Clément mono cartridges.