Did someone call?
That classiczcars thread was a starting point for me, but obviously it’s a case of substituting products available here for those available in the USA. On the dash I did, I used Isopon bumper filler for the crack filling, having used Araldite to bond the bottom of the cracks first. After sanding and priming with a suitable plastic primer, I used UPol PlastX texture finish in both ‘fine’ and ‘coarse’ grades, which if done carefully and combined with sanding can very closely mimic the factory vinyl. I finished off with painting the whole dash with Halfords Flexible Vinyl Paint. Note: I did not texture finish the whole dash, only the repair areas, and blended them in. It can be done to such a degree that only someone who knows what they are looking for can see the difference. That’s less so if you retexture the whole thing.