[DByers]

I am not to in tune with the jewelry business and not sure exactly how much you create or do in house but from your post sounds like maybe you have that capability.
Being a person who runs a small business I would look at keeping the current
location and adding the second. The first could be more of a wholesale, discounted items that are maybe not current or selling well and design repair location. The second new location could be your "retail" location fed by the wholesale location keeping only high end products you have that fits the locations market.

If the new location is a partnership I would suggest a strong written agreement by a professional that spells out every last detail.

Good luck on what ever you decide!