Using all the factors originaly listed I pulled an engine from a Volvo 740 that ran with no problems at all.

However....

This was a hobby sort of thing. If I had blown $200 I would not have considered it a big loss.

And.... Several teenagers in the neighborhood were wanted to do an engine swap and I had a Volvo with a blown head gasket. It was something they and their Fathers could come over to the shop and work on when they wanted to. I just sort of looked everything over and offered advice.

But the point is that using much the same tests as in the original post I was able to source a good engine from a PnP. This was about ten years ago, and I think the price then was $150.