Was it Michael Smookler? We went down there too
He's based in the London Diamond Bourse in Hatton Garden - you have to take ID and go through enormous security ... cameras everywhere! Website http://www.london-victorian-ring.com/ - not just victorian designs but also art deco, Edwardian and modern - excellent service, no hard sell and will find you what you are looking for - if you want to design your own he'll do that too.