In my opinion there are too many unknowns and buying it blind is a gamble.
From looking at the pictures it needs new weatherstripping £800 plus import duties, the digital dash needs new polarised filters, you can see the burnt out areas, and at least the 12 pin internal connector changed, horn button missing from steering wheel, hood release cables, early 16" tyres are super expensive (£500+ each) if it needs new ones.
I think you will be better off sourcing one that's already here, £10k is a good budget for an early one.
I have a red 86 auto that I have been restoring, if you can do the work yourself it is a lot cheaper, if you are set on that colour combination it might take a bit of patience.