I have one of those old Webra .61 Blackhead engines and mine is missing the muffler too. I've wanted to start this thing up for some time but the neighbors would probably get a little upset at the sound of a .60 size engine with open exhaust.

My Webra has been modified with a standard C/L venturi.

Back in 1969 the Webra was the engine to have in RC pattern events. A very good-looking design.

One of these days I hope to add a Supertigre Bluehead .60 and an OS .60 Goldhead to my .60 shelf.