Could it even be a Hard Rock? Later 90's Hard Rocks had the noodle too. Though the seat clamp band area looks to be RockHopper or Stumpjumper.
Seller states someone sold it to him as a Stumpy, though admits this may not be true. - "I've been told this isn't a specialised I was sold it in good faith that it was its had a respray in its life and other parts fitted I think it is the original colour looks to have been a grey of some sort its sold as seen take a look at the photos and make your own mind up "
1995 or 96 Rockhopper is my best guess. Definitely not 1991: the seat tube noodles were used from about 1993-1996. Don't think it's a Hardrock: the head tubes tend to be a bit taller. The lower end 1995 and 96 Rockhoppers still had quill stems; upper end used ahead. Seat post collar is 1995-96-style for Stumpies and Rockhoppers. Likewise for rear dropouts. My 1996 Stumpies have the same seat post collars as the advertised bike, (while the earlier Stumpies had different seat post collars) but the frame numbers begin with 95 and 96, so I reckon it's from 1995 or 96 but not a Stumpy. Best guess, then, is 1995 or 96 Rockhopper, but leaning towards 95 based on the frame number.
Curiosity is urging me to buy it to investigate further but rationality is telling me it's a waste of time, money and garage space.