I still have one someplace... I remember it as a little different from that one... possibly shorter and more of a "step up"?  Might work good on a highly modified CT1?  I think we used it with a 32 carb from an RT1, even after a lot of jetting it ran better with stock carb.  Kind of sluggish and boggy with big carb.  Sounded good though!  I think the carb was louder than the pipe!   It was a friend's bike with a pipe and some mild porting.  We were kind of limited with jets and I remember we may have used number drills to make a big enough main jet?  No Internet back then so much harder to get parts.

Magazine article had a Vesco modded CT with bigger carb...  they TIG'd the stock stud holes and flange and re-drilled/machined to not mess up the inlet length tuning...  piston port two strokes don't like the carb too far away.  I think Vesco set a 175 speed record at Bonneville back then. 

And we had to change or make new cables and use a different throttle if I remember correctly?  We might have just done that anyway because autolube was removed.  Had to be 40 years ago so I don't really remember.