and here's the response from John P:
"well being new at Williams I was experimenting with a lot of stuff. it was encouraged. So on WCS we looked at trying to make the game really hip, so molding the flipper bats in teal polycarbonate was the trick. Zaccaria did this as well as Bally in the 80s.
But in this case, with advice from Pat Lawlor, the bats did not last more than 3 days on a game. The design was not made for this material. So we had a few made and it stopped there."
So, it appears I have a neat conversation piece here, and am probably better off not using these bats!