Our Transatlantic Cousins seem much happier using eBay for 'big ticket' items, and this is probably one of the cheapest forms of advertising you can get...
I think the mention of 289 in a couple of places is purely a lack of attention by the writer of the ad, there`s no reference to the engine having been replaced.
The chassis plate was in use from the start, as referenced
HERE:
But it must be said, the one in 2047 does appear slightly different with different stampings.
If I was spending this much money on a car, I would certainly be booking a flight before parting with any cash, or at the very least, getting an expert over there to pay a visit!