Well as to the blue one on the stand in the picbucket...
Price may seem a bit high but then ask yourself if the guy (or his surroundings) seems like the type who'd go to all the work of JUST PAINTING an engine like that and then try and sell it as a rebuilt or refreshed?
I mean if 'I' was going to the effort to make it all look that good I'd go ahead and do the mechanical while I had it apart.
If he's already building something else then He's a builder not a scammer. But that's really why it's your decision or I guess as they say down your way "trigger to pull".