I ground my first muffler apart like you did. Later, I discovered that you can usually carefully pry the crimp apart with a screwdriver to disassemble the muffler. When I put it back together, I just smear a little JB Weld on the joint, press it back together and re-crimp with pliers or some careful hammer taps. Works great and no leaks.

On mine, I braze two 7/16 or 1/2" i.d. outlet tubes. Seems to work great. In one review I read about the G-26 Zenoah, it made more power with larger outlets. If you get too carried away though, they get pretty loud and the idle and transition isn't good.

Questions: Which type of silver solder did you use? Sta Brite, or the real high silver content type? Also, have you run this and will the silver solder hold up to the temps involved? I braze mine, but if it works, the silver solder would be better for the thinwall brass outlet tubes I use.

Here's a pic of a Homelite muffler with smoke attachment, and a muffler I made out of plumbing parts for my Katana.

Thanks,
AV8TOR