I just had all the plugs out and the outer two were ok if not a bit fury. The inner two however were soaked in oil. The oil had started to well in the coil recesses, these inner plugs were not torqued up properly or they had loosened which could explain oil passing the thread and collecting. I put the scope in for a look, I could see a general cross hatch scoring which was mostly light. There were notable heavier marks. all 4 bores were like this. I have the pics if of interest.