So this week's Mephisto (at least, the one on the Crossword Club site) asks for entries to go to 1 London Bridge Street, whereas the Prize Puzzle details on the Club site has the Colchester address. I'm assuming that the latter is correct, and there's just been some sloppy proof-reading of today's copy, unless anybody has any better information.
Yes, but I'm an old-fashioned sort! And if the printed version is wrong, those who eschew electronic communications might be consigning their entries to a waste-basket.