Very interesting topic, thank you for reviving it, if only so I could read it! I don't think the only unique gift of the Dwarves was their jewellery skills ...
I always imagined dwarven psyche as the kind you are using when you pick at a scab, or dig a massive pit in sand, or gut out a hole in a school table with a pair of scissors; it seems pointless and slow in hindsight, but you think to yourself later "
I just sat there and did that for HOW long??". And you get this massive great hole as a result.
I could see that patient, never-give-up psyche working in a Dwarf 24-7 (and I bet it would be cool).