cjaronica
Sorry to hear the o rings did not work out. You are right about them being a little harder than the clear ones that Larry sold. These are 70A durometer which is the same hardness as the red o rings that came with many of TTW's tables. I think the special clear ones that Larry sold were 50A. I could not find anyone who was making that size and spec.
One thing to check, ( I am sure you already know this ) that the drive motor is not too close to the ring on the platter. That o ring should barely touch the outer ring attached to the platter. I know that if the motor is tight up against the platter you will get a significant amount of noise through the tonearm. It is a pain to get setup correctly but when it is done right, its sound is magic !