9437 appears to have a somewhat squared shank; 9442 is a close match. The bevel on the rim of the pipe I have is sharp on both edges. There does seem to be a slight radius to the bevel. The photo of the 9442 may show a worn rim.
As for Perspex stems, I run a cleaner soaked with lacquer thinner through, even leave it sit for several minutes. Then a cleaner with water, and a dry cleaner. Rinse with cold water, and dry.
Polish the airway with a cleaner wet with mineral oil and Rottenstone chucked in a drill. Slow speed and move in and out. Then a dry cleaner.
I’ve done this over several years and never had an issue with it crazing, or clouding.