Guys,
You helped me out with the first one, so I'm going to ask for more sleuthing from you.
This one came out of a junk box that came from a "stunty" source. It would seem to be for old Supertigre .46. I decarbonized it and polished it up since I needed an ST mufflicator. Turns out there was some nice aluminum under the crud. The brass strap was never used with this muffler, but it was in the junk box. I straightened it a bit, but the holes would need to be drilled. I'd probably just make a replacement to give myself some edge distance on the holes. The manifold is threaded for 6-32 screws. The stinger ID is about .320"; effective pipe length around 5-1/2". Boss with threaded hole for pressure tap included. Weight with strap and bolts is 53 grams, so it feels light for its size. Nice brazing/welding.
This one has the manifold offset from the centerline of the main chamber, which now seems to be standard practice, probably to promote flow thru the 90-degree transition. The Semco muffler did not--the mainfold was centered on the tube.
Seems like the biggest dislike would be the angle of the tube to the manifold. It won't sit in close to the fuselage, but would extend some 3-1/8" from the centerline back at the stinger.
Who made these? How did they compare to other mufflers for stunt run characteristics? Any direct experience with one on the ST.46?