So prop load was not the problem.

I think the idea is that the oils runs down the rod and into the bearing via that hole. Maybe not the best idea, since that is where maximum pressure is. Perhaps there was a burr on that hole which is why it picked-up and marked.

I have 2 of these engines, both have had many flights on Methanol and several on petrol with no big end issues. Your bronze bush will be a better item than the original I am sure.