I haven't been on site to see the arrangement, but as I understand things these are high up somewhere on the roof and allow access into an otherwise inaccessible void space. I don’t think they are even visible from the ground, so all my efforts will only ever be seen by a few maintenance workers!
Have to say I'm liking this bronze stuff to work with. The leaded glass is held in with 3/8" square, bronze retaining beads, screwed in place with 3/16" Whitworth brass, slotted, raised countersunk screws ... you try buying them these days. I managed to persuade them to accept normal countersunk screws but still had to have them made at considerable expense. Anyway, where screws had broken or, in some places been replaced with oversized m6 screws, it's really easy to weld the holes up then redrill and tap.
Similarly where corner joints on the frames had broken, it's possible to make an almost invisible repair if you grind it back carefully. I've found backing the holes and sharp, external corners with rusty steel works quite well, otherwise if you get things too hot, big lumps melt and drop on the floor!
