I may be mistaken, but I think that is a California Friendship(?) car...
They are well made, and definitely are somewhat heavier than the typical Steib or Velorex, and possibly close in weight to the URAL/DNEPR rigs. They are a good quality rig, from what I've heard, but your chances of "flying the chair" with that on an R65 are pretty low. On the plus side, I bet it is very stable on right hand turns.