Hi Terry
That's a tough one to answer really.
My only alarm bells at this stage are that they say the oil pump has failed....how?
Oil pumps wear and can block up, drives can shear and other factors can exist to lower oil pressure but to completely fail....bit confused by that one. Also, surely the oil pressure light would illuminate?
I would certainly research the cost of the pump and see if you could supply them with one from a cheaper source.
Bore wear, that can occur on overrun (piston slap) but to be fair, a rebore and new pistons would cure that.
However, if you look at the score marks on the piston skirt they are clearly on either the thrust or the non-thrust side BUT when you look at the score marks in the bore they are on neither the thrust or the non-thrust side but within the gudgeon pin area.
Make your own mind up....???