Model Aviation Cover (Corsair)
Malcom,
Yes it is a Jett muffler. They call it an "In-Cowl" muffler, unfortunately, it won't fit "In-Cowl". Its close, but I will have to do some pretty good cutting on the bottom. I believe it is on the Jett Site, but their site can be tricky to navigate.
As to the review, I'm just your average everyday kit builder. Not a beginner, but far from being an expert. I have problems, and make mistakes like everyone else. I hate the kit reviews, that say everything went great. Sometimes I misread things, glue things when I'm not suppose to, sand too much, etc...