However, I've been trying (but failing) to find a picture of the prototype T160's silencer on the end of its 3-into-1 exhaust ,
From the side, it looked like two reverse-cone silencers one on top of the other. However, looking from the rear showed one of the 'silencers' was blocked - the exhaust was directed back and forth within the silencer before emerging from the single outlet.
There is a school of thought that says this was psychology to make the Notrun-type annular-discharge silencers acceptable - on the lines of, "Look, this is how ugly we can make it" ... If you have Whatever Happened To The British Motorcycle Industry, picture on page 266.