Originally Posted by cycle_maven

This one screams for DIY- it's only a Grand Prix, not something irreplaceable.

I'm a part-time silversmith, and one of the tricks we have is to use different alloys that melt at different temperatures to join complex partially-assembled pieces. In the case of that broken stay weld, just clean it up, file it to fit tightly, flux it and flow in a little silver alloy- the brass/bronze used in the original joint won't even come close to melting at typical silver temperatures. A Mapp-gas torch would be hot enough, but it will probably require the whole seat stay cluster to be heated- best to use oxy-propane or better and the heat can be localized better.