Damn, John retiring is very bad news. Those of us who already own the utterly unique London and Decca pickups are going to have a hard time finding someone else to service them. I better give him a call!
As for acquiring a Reference: don't hold your breathe ;-) . I would never sell mine (for any amount of money), and I'm probably not alone in that sentiment. I used to see one pop up every few years on USAM, but haven't in quite a long time.