Almost no oil pressure help

This is dumb, but I have to ask. I had low pressure from a "rebuilt " but never fired engine once. The oil pan was mashed a tiny bit from where he had been setting it down in the shop. I pulled the engine back out and did what you are doing... I pulled the pan off and found the oil pump pickup had made a mark in the pan. It was blocked at the bottom. I put a better oil pump in, flattened out the pan and was money. I don't know what pickup he used but it was way too close to the bottom of the pan with the shroud missing.... It was sealed up on the pan. I chased that one for a week. Another thing, was it really rebuilt? I'd be pulling the pan and checking the screen.

This is not dumb and could all be very possible... It was my initial thought so I may just start with that as well.

The heads are crystal clean with shinny valve springs... If those aren't new the only other way would have it severally power washed.