I see exposure to quite a bit of humidity, the rings could easily have rusted at the spot they sat, I see rust inside one cylinder. The carb and intake are corrosion tarnished as well. No way to me at that price. Then on top of all that is the trusting the machinist issue. So many deals like this turn into pure crap, buyer beware. May be fantastic deal but I don't go for stuff like that.
I've seen new parts simply sitting in a non-temp controlled garage turn into scrap in that length of time. The hot/cold cycles just rust parts together to ruin them. Most will be OK but assembled rings to bore is asking for it.
That's the pessimist in me talking of course.