Realistic buying price of a s8 d2??

[Bushido]

I appreciate that the s8 is now attracting some attention and reviews from classic car magazines and see people stating in adverts that there are as few as 120 currently registered on UK roads (accepting there will be as many stored away somewhere too).
Would people mind please sharing their experiences of either looking for or selling their s8?

As people will be aware, my car is still pending a gearbox rebuild. I keep running the figures for this and finding myself torn between going ahead and knowing that its safe expenditure and will always be recouped should I decide to sell it or accept that I can all but pick up another s8 for the cost of the rebuild? (albeit with a list of expenses pending...)

The curve ball could be that I have the box rebuilt and freshen up the whole car with the intention of saving it from becoming a donor and selling it straight on again. So, that brings me full circle back to the question - what would be the likely resale value of a very fine example of an s8 with a fully built box , service history (including belts etc) and new brakes / tyres etc which would all be done as part of the refresh. I'm figuring that I would need be looking at £5k to be justified?

Over to the people in the know please. Any experiences or thoughts much appreciated. Seasons best to one and all