Scored Main Cap Bearing - Ouch

Mmmmmm.... Scotchbrite is frowned upon. The carbide particles get get everywhere. I'd lightly polish with 600 or 400 wet-or-dry. Crank is not great but no horrible. I would plastigauge it too.

Good idea on the pump examination. A lot of scoring there indicates a general level of dirt/debris. But that can only be told if this was a new pump at rebuild. Again, examine more mains/rods to see if this was a general problem or localized. The more info you have, the better the decision, IMHO.

Not sure I am following the comment on the chamfer being no touched.... looks chamfered to me...??? But I might not be seeing it right. It looks like the debris was caught around the hole and spun around and around before it disintegrated.

How is this engine to be used OP?

BTW, I don't see the factory knurling/fine grooves on the seal surface. Maybe it may not be visible. But if that is gone, then I think you need to change away from the rope seal. And if that is a rubber rear seal, it looks kinda burned/melted to me....???