Try putting your TT and electronics components on a partially inflated bicycle inner tube, Keid, and report back on what you find. If your TT has an uneven bottom, put it on some home-made roller blocks (concave plastic furniture cups and ball-bearings) resting on a light plywood board resting on the inner tube. It will probably make a bigger difference than the silicone rubber tweaks.
Thanks for the input SS, but I have just purchased new speaker cable (and burned it in), and on Wednesday I am getting my new speakers. They will take around 200 hours to burn in, so I will be busy with that for a while.
I have read that many tweakers have achieved great improvements this way, and apart from the looks of it, and the constant inflating, it sounds like a great tweak. Of course there are ways to escape both "down sides", and I have thought of trying this more than once. Perhaps one day?