Nothing like resurrecting a thread.

After I picked up some of the washers that @Thraug recommended above. We had some success with them but found them somewhat lacking. @Funny Defcon hit upon the idea of a two washer system, with the above washer glued on top of a 34mm diameter washer that perfectly matches the base so that they nest perfectly and measuring distances is even easier. Since the larger washer matches the plastic.