Brian
3rd post this thread should work on clearing up what the question was/is.
How are the children in Jim's playpen doing? Hope they are getting along.

This winter may have time to do some good measuring of pistons and sleeves to help for sure Id what Flyingtigre has.
Current work on trimming out Stunt planes and retraining pilot leaves not a whole lot of time for engine work.

Mysteries, I like good engine mysteries!

Here is the payper work, box and engine, Super Typhoon.
4 of these were brought back from Japan, although 3 have been traded of over the years.

Camera is lousy at close in photos.
Pictures do seem to clear if zoomed all the way(2X click)