Pryso, Thanks for that input. I was unaware that the rod in Albert's plinth actually goes thru to the bearing housing. Very ingenious. So you're correct; that IS different from what Raul has done. You've given me some food for thought; a similar device could in fact be placed under a slate plinth.
Raul, As regards your remark that the SP10 MkII and III may not be the best of their contemporary Japanese brethren, that may or may not be correct, but the point is moot, since those tables are so rare and unavailable. In any case, I would bet that any of them would also benefit from re-thinking the plinths they came in. In many cases it was a big hollow wood box, a nice box, but still a box. Last time I visited my son in Tokyo, I saw a mint Yamaha GT2000 sitting on the floor in an audio salon. Sadly, it had been promised to another customer. The price was actually quite reasonable, about $1500, I think. Anyway, the subject of this thread is the SP10 and its variants.