You can modify a muffler. The photos show a Veco .19 B.B. with a muffler from an unknown engine with the threaded portion of the muffler that attaches to the engine exhaust stack cut off so that the overall width is the same as the exhaust stack. A drilled and tapped hole on each side where the ears were cut off will hold the strap, which in this case was cut from some scrap .035" thick banding material using a pair of aviation snips. Form it around a dowel of similar size as your cylinder, put a couple of 90 degree bends in the end and use a bolt to pull it up tight, or, if you want to get fancy, use a narrow worm drive band clamp. Cheap, simple, effective and in my opinion, looks pretty good.
Chris