I would not trust this seller.
A couple of years back I noticed that a few HP-16C he had listed all had the same photos, clearly implying that he was using the same photos of *one* of his calculators for all his others.
When I questioned him about it, he implied that because they were all the same in his opinion, there was no need to post actual photos of the item. That's even though the implication (sometimes explicit) in each listing is that the photos are of the actual item for sale. I noticed the same thing again and again on subsequent listings.
He is obviously still doing it, as witness the comments in neutral feedback he got recently.
So I wouldn't even trust that the HP-15C in the photos is the one he is actually selling in this auction. Assuming it is (and even if it isn't) it also looks like an HP-15C I saw doing the rounds on TAS last year...Recycling is good ;-)
Having said all that, the seller has "top-rated seller" status, so despite his deceptions (whether intentional or just through not caring), he must be doing something right.
Philippe