I haven't found a easily-available standard glow-style muffler that will fit this engine. You might want to contact the folks at Bisson - perhaps they can adapt one of the 'sport' muffler they offer for some of the big glow engines.
Bisson actually makes a
Sport muffler specifically for the MVVS 1.6. It's Part Number 05518. I think it may actually be for the MVVS 1.6 glow engine since there's a pressure nipple on it. It weighs a hell of a lot lighter than the MVVS tuned pipe, so I may give it a go.