I finished the reconstructive surgery and it turned out OK. The advice was good - thank you all.
The SEM material with the fiberglass mat seems strong. The USC SMC filler was tricky for me but I have no experience. It kicked over faster than I expected and cured pretty hard but it also adhered well and seems strong. Both the SEM adhesive and the filler were
much harder to sand than the SMC material in the header panel. This made it hard for me to keep contours close, especially with all the compound curves.
All the little dings along the edge were tedious but after about 5 passes with the filler, I figured out how to make them be gone.
Onward!
Mike