Oooh that's bad
That is from a careless windscreen fitter (ie all of them) trashing the paint taking the screen out, not dealing with the scratches, and then moisture getting in and creeping under the paint. That's glass out and respray the whole roof to solve it, and tbh with it getting in to the aluminium like that you may not even solve it by repainting. I'd walk away from that one, even in the lovely santorin blue. So many D2s have been spoiled by awful paintwork now its very difficult to find a 100% original example. We have most of them within the forum now I think
I can't see the insta link, but excited mechanical thrashing for a few seconds on startup is fine. A loud clatter or rattle on a cold start is very not fine and indicates the cam chain tensioners need replacement (£1500 in parts).
WITW is 'What's in the workshop'. My restoration threads started out with that title and then got shortened to WITW, so search on 'workshop' as well to find the early ones. They are all in the Daily Banter section and go back about 7 years I think.
Btw, there's a <100K grey example on ebay too which has been for sale forever. Run screaming from that one - its trashed and likely needs a gearbox rebuild.