I remember your thread . That's bad *** that you drove home like that. Now, you show the groove on the exhaust stroke but remember that wont effect compression until it makes it to the compression area of the rotor housing. Do you have any pictures of the top of the housing to the trailing plug hole???

 

Nope, the housing is long gone. But there were scores (not nearly as large as the exhaust side) near the leading plug as well as seal damage.

 

Keep in mind he had piecs of apex seals missing to create those craters in the exhaust stroke. These engines will run with a surprising amount of damage.