I cracked the left sidecover on my 76F so here is what I did.
I used regular PVC cement (the stuff for PVC plumbing pipes) to weld the crack closed and also drilled a small hole at the end of the crack to stop it going further. The cement made a strong bond, better than I expected.
Used fiberglass cloth and epoxy to beef up the area of the crack.
I decided to beef up the backside along the top and at the tabs. Using epoxy thickened with a high density filler I filled in the area around the tabs .
Used some glazing putty to smooth out the welded crack and gave it a shot of primer while my helper checked out my work.
Sanded the whole cover with 400 grit and gave it a few coats of primer. Crack is now invisible and the I feel the cover a bit stronger overall.