To the best of my knoledge WD-40 wont hurt the poleys unless they are thoughs new advanced ones that arnt suposed to be sprayed with anything. But i would say that you might want to use a better rust stopper then WD-40, maybe try some T-9 or Tri-Flow. (my two cents)
I removed the tunnel from my capri a couple of months ago. I had trouble getting off the fiberglass peice that is just above it to allow water to wash over it. But once i got that peice off which took a lot of work becase of the glue used the tunnel came out easily because mine...