Your car doesn't have a 'pattern' wing as they were never made.
I'm not so sure about that, no positive evidence, just a feeling that there WAS a company making pattern panels for all sorts of obscure stuff, in Denmark IIRC and they may have made Dolomite wings. Can't quite remember the name of the company, getting old I guess!
But you may equally be right and it's just a badly made and badly fitted NOS wing. Some of those turned out after production ended (and in truth, on late production cars) were pretty awful, simply because the tooling they were made on was beyond life expired! Even earlier cars had panel fit problems, there is a well known production line pic floating around that shows a Dolomite with a truly AWFUL gap at the O/S/R door! I have seen MANY original cars with similar inadequacies. In fact, if the gaps are really good all over the car, chances are it's been restored! I had to have the shell jig straightened from accident damage on my own Sprint and the guy who did it joked that it was straighter now than when it left the factory. Since he worked to 0.1mm and the factory emphatically did NOT, this was true and not that funny to me, but i'm pleased to have a car that straight! Even so, I spent many hours getting all 4 doors, bonnet etc to fit perfectly to MY satisfaction!
I was already aware that it's an early car, since it's on the OP as VA2089. Crucially though, it's not quite one of the "first 2000" and even if it was, there is no particularly special extra value conferred on them, only the first 20 press cars from the Geneva launch are really worth a bit more and I would say all the known survivors there are accounted for. Along with the "Motor" magazine (or was it "Autocar"?) long term road test car and the handful or so of surviving works competition cars. The first 2000 are certainly a bit more sought after by the cognoscenti, but outside that limited market, a Sprint is just a Sprint. And it's value is determined purely on condition. As it should be!
I guess that GRP panels will lower the value a touch, but probably not much more than the difference in original price of the panels concerned. What it WILL do is make the market place smaller as anyone looking for a pot hunter, or an investment, probably won't want it at all. Personally, I don't think that's a bad thing!