The spare cylinders measure 94 mm (3.675 inches). Neither engine have been opened so I don't know the internal condition. These were part of the deal when I bought the boat for the KR-2 I just finished. There is no sheet metal, since they were to be used in a plane.
Both engines have serial numbers with a prefix of C V. I will send pictures to Jim and Ray off-line. Jim Vance va...@hbcomm.net