If all you're saving is the plastic, you're not saving much. With good hardware, it's worth re-taping. You'd probably be better off buying some polycarbonate and making your own flashers at that point. I'm not sure how often they do it, but I picked up some flasher blanks from Fishermans with hardware for $1.00 each if you're excited to do some taping.

I imagine a wire wheel would make quick work of flaky tape (and a nice mess).