Seems like nobody is responding to your request.

I would suggest silver solder as a repair. On the cheap, you migh try using J-B Weld but be sure to do a thorough cleaning job before application.

You may also send inquiries to the folks that make custom mufflers (You should find them in the Mag ads). Indeed you may inquire at the engine dealer (I belove that is Horizon Hobbies for advice and suggestions).

You are pretty far north, keep warm!

Cheers,

Chip