Hi. Here's a pic of how it would look (similar anyway!). It depends if you want the sink to stand out or for the worktop to look seamless. As you're going for a shaker have you consider a butler or Belfast sink?

When we reserved the stone slabs at the stone yard we did indeed sign a disclaimer, it was our understanding that we couldn’t have the slabs if we didn’t sign. When I check their website, they don’t have the granite listed anymore, but then I’m pretty sure that we had the only 2 slabs they had of this granite, so this would make sense. Unfortunately we don’t have pictures of them. Thank you for your advice, I’m located just outside London so I will get in touch with Rossi Stoneworks. I just felt so clueless, so having a name of an expert to contact is a massive help. I did wonder if the marks were due to ‘sucker pads’ or something similar and raised this with the stone mason, but he said that wasn’t possible (I can’t remember the exact reason he gave), but I agree that the marks look so uniform in shape, which (I believe) points to something machinery related (as opposed to something naturally occurring within the stone). I fear that the disclaimer we signed may pose a problem - watch this space. I will add more on here with updates, in case anyone else experiences anything similar. Thanks again for your comments - I really appreciate it, I don’t feel as helpless now.

I know granite is porous, so I wonder if a substance like vinegar or lemon juice was accidentally left on there for long enough to cause damage? Was the granite sealed after installation? I wonder if it could be sanded down then re sealed.

I would leave it, add a plant or two and some brightly coloured towels in the interim. It looks well finished. Honestly I have seen far worse. The dark tiles are not to everyone's taste but I wouldn't bother with half measures. I have a really grotty bathroom to renovate and it's only 3 years old. I could really show you bad tiling and tile choice and a big piece of lino for the floor. I would love to have that showeroom!