I was thinking that as well MF, but on closer inspection this isn't a clip on muffler - it has the tightener bolt on the muffler. So no gasket
You can wrap the motor outlet with a bit of heat proof tape (like muffler wrap) to bulk it out if the muffler is not a tight fit.
Speaking of which, Tomkatoz if you are still struggling with the g2 carby, I am getting rid of a 1977 Victa 2 stroke with g4 carby. Came off a knackered Victa Contessa I was given.
Ran fine a year or so ago, supposedly recond in the early 00's. Mechanically its good, visually its bad. It needs one hell of a degrease and the cowl is stuffed from plastic decay, but you could swap the barrel over to yours if you would like, or swap the whole motor over.
Its all there including snorkel and throttle control
It yours for free if you want it - its in my way. Send me A PM if you would like it.