Ok simple test to prove or disprove this is put a plug in the decomp and a plug in the plug hole and see if you have spark.
Is this what you meant?:
I tried a plug in the decompressor port... No go.
I had the plug in the spark plug port and a spare spark plug not connected to anything in the decompressor port, no spark, very difficult to pull, and I heard the "clang" sound.
the wear pattern on the cylinder is classic one after dirt been ingested - the intake side will be similar
Nope, the other side of the cylinder is perfectly smooth, the only damage/wear is on the exhaust side.
