I bought for Hook from these guys and they do SS too in a set of 3 for some reason;
http://www.pinballpt.com/prestashop/hole-protectors/75-scared-stiff-hole-protector-set.html
I had the same problem, I spoke to Cliff about it and he made a new one flatter than the original that's been fine ever since.Had a cliffy fitted on my SS spiderhole. Had to take the back bit off as the ball would always hang there.
I bought for Hook from these guys and they do SS too in a set of 3 for some reason;
http://www.pinballpt.com/prestashop/hole-protectors/75-scared-stiff-hole-protector-set.html