Hi. I also have had two of these stuck to my letterbox in the last week – really annoying to get off. Anyway, I just googled the number and saw that there's a pretty long thread from 2013 on the Chsiwick forum about the very same thing, and a member of the Police actually posted that this was a genuine company not a scam (there's talk that people 'identify' houses for potential burglary with these stickers).I phoned the number, it is a genuine locksmith from Cricklewood and was apologetic about the stickers. He said they 'do the rounds' every few years for advertising.
Steve Burnham ● 3131d