Update- the nuts that were jb-welded on, they fell off the first time I got the saw in some wood and really warmed er up. They just popped right off. Next step… I weld on a proper baffle.
If you haven’t run the welder yet, there are a few different high-heat epoxies you could try. I used some to patch a cracked exhaust manifold in my jeep; the one I used was good for 1,000-1,000 F or so and worked just fine. BTW how does the say cut now that it can breathe?