That's a possibility too I suppose. I hadn't thought of that. I'm not sure what my local availability of non toxic lead filler is around here tho. I had considered 3M panel bond adhesive as well. I'm trying to eliminate as many joints and seams on the car this time around. Some like the header panel I'll have to live with, but others like the quarter extensions I'll fabricate my own out of steel and weld them in. 😀
just remember that panel has to be removed if you ever need to remove and install the back window