I'll take a different tack from Fred. My gut feeling is t's a newer saw, 1982 to 1993 or so, with a pea green paint job. I too find it strange to change out the guts on a 66 unless there was a really bad accident along the way. I can't understand why he didn't paint the entire saw either, but that's just me.
I'm more concerned with the statement:
Something smells funny... I can see machining a table top, but there's NO reasonable explanation to machine a bottom of a top. Besides, the only viable way to machine a table that size is with a Blanchard grinder. There's very few places that can handle tables that size and they charge accordingly. Unless there was a major flaw, nobody in their right mind would even consider it. In short, I think the guy is blowing smoke, my opinion obviously. Ask to see a machine shop receipt.
I'd be cautious, find out what's the real born on date, the trunnion color and box color don't coincide. The box is obviously newly painted, might or might not be true to form. The trunnion doesn't appear repainted, why? Is it original? If not, why not? Not that any of this is a fatal flaw, it just might lead you to more work than you anticipated such as replacing bearings that never were. I'd consider fair value accordingly though.
The 3ph motor is really not that big a deal. A VFD, RPC or motor swap will all fix that for about the same cost.
Mike
Almost forgot, Fred, that's a heck of a restore! nice, very nice!