Yes - thank you - those are the ones, kindly given to me by toaster, so I wasn't sure which brand. Well done to John R, they were very simple to install, they sound great, and the deck is more stable in every way. A fundamental upgrade and a bargain. Maybe the Vilchur suspension wasn't that clever after all.
It still doesn't quite match the metronomic locked-in pitch of my SL-1210, but it's 64.3% closer to competing with it and my other decks now, and I'm happier that I'm not wasting good diamonds on exquisite reproduction with third-rate pitch stability.
BTW, my power amp upgrade path was Naim -> Linn for the reasons mooted above, and then Linn -> Behringer/passive(Creek) because I couldn't hear a significant difference. I still love my Uphoriks/active 242s, but I'm always willing to be convinced there is something better.
Listening without price or brand prejudices is not easy, even on the rare occasions when you have the opportunity. I have certainly reached the conclusion that high prices are no indicator of true musicalityfulness
™.
My current subchassis is the Alto with a standard cardboard arm board. A decade ago, after listening to several Klimax Sondeks I decided to cease throwing money at the old girl, and I even sold or returned my Greenstreet. My Sondek is now at a level of satisfaction that I could contemplate further upgrades if I win the lottery. Most importantly it's now a good platform for testing tonearm compatibility and a pleasure to listen to. Try John's grommets.