Obsidian plinth. One should remove the original footers
which are worthless and substitute them for AT pneumatic
636 or the bigger one. Your last question looks to me more
relevant than the first. Those Obsidian plinth's are very
expensive so you should anyway buy the SP-10 Mk2 (or Mk 3)
naked. There are all kinds of plinths for the SP 10 with
ditto prices (see:ebay.uk).