There is a sequence of videos on Youtube showing Hirose scratch building and modifying lugs, a bit long winded but I found it interesting. Looks like he is gas welding them. This is the first: youtube.com/watch?v=VbBTZrOS56Q
William.
Clearly the man doesn't believe that brass fillets are strong enough - or they are aesthetically upsetting to him. That's a lot of grinding, tac welding, finish welding and more grinding.
Or is he welding everything because he's going to use brass to braze the tubes rather than silver?