I would cut out the rust area, and graft in some sheet metal from a donor bug. I belive any '64 and later will work for donor. There's still some bugs out there that are not rusting in this area. This is not the easiest way to fix, but the way i've done it, due to my sheet metal skills from my day job

. I'm interested in what Laz has done too. There's more than one way to skin a bug...uh i mean cat

.
__________________
1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG