My beginning of the year market guide written to help those who don't follow the market closely to then set their agreed value with insurers would pitch this around £12k, I'd likely bump that today to go with £14k on this particular car to allow for some Supra inflation and factor in the rare 6 speed OE box with everything in really nice condition as its insured value; private resale value would normally be 15% to 25% lower. So, if it were my car to sell I'd be pitching it at £12k to £12.5k ovno sale price.
Exceptional cars will always attract exceptional prices but not many of us actually own exceptional cars because by their very nature, they are the exception. I think the significantly higher values mentioned could apply only to a truly exceptional
car.
PS - Comments assume the car is VIN matching.