I agree that the front seats are highly likely to be replacements, Shaun. Welcome to the forum, by the way...
My second Volvo, a '72 145 DL, also had mismatched seats - black vinyl in the rear and the same colour leather to the front. I was told that the originals had worn out and were also badly sun damaged, which is why they were changed.
A later car, a 245 GLT, was an ex-embassy car and equipped with a/c. This came into it's own when we toured Scandinavia with some Swedish friends in the hot summer of '95. I don't remember for sure at this distance in time, but I have a feeling that it was still running R12 refrigerant and not R134a. It may pay you to check this if the system should need regassing.
As 'Moomoo' observed above, the 2 series cars are the arch-typical Volvo, embodying all the virtues that made the brand a house-hold name for reliability, safety and longevity. The 245 is also a consummate load carrier and an excellent tow-car. It's only limitation in my opinion was the one-piece rear seat - an omission that was later rectified on the 7 series, which rendered them much more versatile in that respect.
I hope you enjoy your new car - as I am sure you will! I often wish that I had kept hold of my GLT, but at the time it was just another old car. In mitigation, I did keep the 745 GLE that replaced it for 18 years. Be warned, Volvos can have that effect on you!
Regards, John.
P.S. While I'm not aware of any 'limited editions' being produced (but that is not to say that there were not), don't forget that the Torslander was very much a run-out model for the 2 series. As such, Volvo may well have used up existing stocks of parts, which might explain slightly varying specifications across the range. J.