I have one of the new Spacedecks with the new Ace Space arm. I have been looking at an isolation base for it to replace the standard Nottingham base. I wanted to go Neuance but they don't seem to be made anymore. Well, with a little time on my hands I stole the Stillpoints from my CDP, the Herbie's Iso-Cups with Ebony ball from my tuner and proceeded to attack my Spacedeck. I tore of the little rubber "feet" that ground the Spacedeck to the plinth and guess what, the Stillpoint ceramic ball snugs right against the thread hole without anything touching the side. Very Clean. Now, I removed the little rubber "feet" from the motor base and the Herbie's fit so well that it looks like they were custom made for each other. Level the Spacedeck, adjust the motor a little to line up the belt and play an LP. After putting a bandaid on my chin, from where it hit the floor at the sound my little Spacedeck was making I went and got a freind who has heard my system more than a few times. Just had him over for "coffee". When I was halfway through the first LP he was asking what I did, did I get a new he was suprised at how much nicer my system sounded. I then showed him the changes. Took the Spacedeck into Outerspace for sure. Now, maybe I do need a new Cart. Just wanted to share a success story, I will post pictures of the upgrade soon.

Looking forward to the pics.

Are you still on the original Nottingham base, or directly on your turntable stand? I used a Mapleshade 4" solid maple base under mine and it made a huge improvement even with the original feet.
High marks on your mod.

I have the a least best combination for my turntable (a Space 294 with Moerch DP6 arm), hardwood floors with a lead filled rack that sits on the floor. I just picked up a used Gingko Cloud 11 and replaced the Nottingham base with it. It is the best TT isolation I have used to date. I like it much better than the sandbox I tried.
Ditch the faux marble base in favor of sitting it directly on something else. I am lucky enough to have a Neuance shelf and this is a perfect match. However, using a maple block, such as made by Mapleshade or Timbernation will reap benefits too.

Two more tips. Throw away the foam cell mat and get a Boston Audio Mat-1. Also, move the motor pod to the front of the table. All these things will have your Spacedeck singing.