My buddy and I picked up two mystery helmets off ebay, they seem to be FP's. Excellent helmets, but they need some work of course. What would you guys recommend to use as filler? I've worked with bondo before, many many years ago. I've also used the putty that comes in a tube that bondo makes, but I wasn't a fan. I don't think that stuff cures right, or maybe I just got a bad batch. Any advice would be greatly appreciated. Thanks in advance!