I've got some recent rattling that I've traced back to the pictured area, where is pretty clearly a blown connection. The two pipes are completely detached.

There are some helpful sources on this problem. Mainly this video:

I can do everything in that video myself except the welding.
But I wouldn't need to weld if I can just buy this circled flange piece complete and install it.
However it seems that is only sold with the entire muffler train, which is expensive.
So I was wondering:

1. Does anyone know where I can get just the circled piece
2. And if not, any ideas how to repair without welding?