Thanks Jack, I hadn't known that the Imperial was made in 24" towed-seat configuration. A key consideration with centrifugal-clutch mowers is getting a stable idle speed, which is a challenge for an un-governed 2 stroke of simple design. A heavy flywheel, long stroke, and low compression might be a good combination to try when that was the objective. Reduced compression is by far the easiest of those to achieve. Do you know whether that engine had a special heavy flywheel as well?
