It will probably be published in the spring/early summer 2021 as they seem to have a 6 months lead time, and have a Routemaster article of mine to run first I believe.
Following on from this thread https://www.railforums.co.uk/thread...ecdotes-of-the-apt.210360/page-4#post-4879526, Simon has now advised that another of his articles, relating to the Routemaster, will be published in Best of British magazine due out on 28th January.