As an ex adman I can only vouch for the clubs that would happily extend membership to single-nostriled pondscum. I used to be a member of Century a regular at SH and an occasional at the Groucho. All serve a roughly interchangeable menu - a sort of unchallenging irony-enriched, steak and fat chips for people who've been a bit lost since the Ivy and sockless loafers were the cutting edge.