[Rumil]

iirc Thorin had 'Halls' in the Blue Mountains but no doubt they weren't a patch on Erebor.

I think Thorin (or was it Gandalf?) complained that they were mere coal-miners these days, presumably rather than gold- or mithril- miners and master jewellers and craftsmen.

But I like the idea that Thorin refused to even hint at giving up his claim to being King of Erebor by taking or creating some lesser title. And the views of the original Dwarves of the Blue Mountains must have been a major consideration.