The bore had similar scuffing and gouging at the same spot you can see the gouge off to the right on the skirt on the one photo. The depth of the gouge in the bore drove me to go to the 2200 diameter pistons. I did not get any photos of the bores, it was just too hard to photograph well. There were 39000 miles on these 30 thou oversize pistons.
I am not aware of any foreign material in the bores. I looked closely at the rings and they look fine.
It is possible that there was some over fueling. The HD8 carbs on my car were badly in need of overhaul before my restoration work and were definitely running rich. Not rich enough to significantly impact the fuel economy though.
If there was sticking at the wrist pin, it was resolved by the time the engine was disassembled. All four of the rods more freely on the pins.