This weekend has seen some progress made. I have cut out the R/R corner and fitted the new corner in and tacked it in place Fortunately the old panels were so far out of shape I could fit the panel straight over the old and had no distortion

The new panel sitting in place

And riveted in place before being welded in

I riveted the panel in place first then tacked it in place there was a small amount of work with the hammer and dolly mainly around the upper curves but when the arch is refitted and filled with filler it will look as good as new. I will also be filling in the seams on the rear under the window so that will finish the corners off nicely