@Waveski: Have you had good success with fiberglass mat staying bonded long term? I have tried doing metal repair like that before and always had it delaminate after a year or two. Any idea what I might have done wrong?
I will second patching small areas with jbweld. I have done that on bodywork and been quite happy with the results long term. I like to spread out the mixed epoxy, then put blue painters tape over it and a flat weight on that. Makes the top surface have a smooth/level finish without making a mess.