My welder plasmer cut a sheet of metal which he welded in place and then used a bit of filler to finish it off. He said this was better then welding on a new roof skin as that would have been hard to match up.
Eh????????
Fitting a replacement roof skin would have produced a much better job(IMO). Just a case of melting out the lead filling and drilling the spot welds to remove the old one then plug welding the replacement in plce and re leading the rear join.
No lumps, no bumps and NO FILLER.