In reply to ultra montane: At the top of the street, is a sub-terranean place on the left (looking up the hill). It's massive, and I mean MASSIVE.
I went in once in november, at least 10 years ago, and reserved an £800 pound bass, and told the guy I would be back in Jan. with my christmas money and pick it up. He said OK, I counted the seconds until the shops opened again after christmas, ran to london and: it was gone
Still, the same guy remembered me, apologised profusely, and offered me a £1800 6 string bass for £800
Now I love that shop.