Being greek i had a simular problem actually.
(mind you, im not going to ask for any money mate ;D)
But i found some resin in a hardware store with powertools, paints etc
I asked for fiberglass resin and they were confused, not knowing what it was. Suddenly one of the people working there popped up saying "Did you mean plexiglass?" and apparently that helped.
As for "bondo" (putty), they gave me automotive body filler, which is practically what you want.
Your pep works looks absolutely stunning and im happy to see something other than the master chief/ODST/the occasional EOD build