I’ve got some exhaust flanges cut should anyone want to make their own exhaust header. The flange is the same shape as the flange exhaust port on the gx200 etc and is slightly oversize to allow a 1” 1.6mm wall steel tube to be stretched to shape (see photos).
I’ve got some extras cut, so if anyone would like one they’re £1 each. I’m also happy to provide a 75mm length of tube formed to shape to save you the bother of making the forming tool - another £1. It’s easy to join this to bends etc to make whatever exhaust pipe shape you need.