ska invita
back on the other side
Thats the problem with a London Bookfair being the "national" one... Once we're over this first one I'd be inclinded to have the same event flicker between Birmingham/Manchester and London on a six monthly basis, perhaps even with trips to Cardiff,Edinburgh, Belfast in rotation every other year. Working with local crews to add local flavour.
There's also the Anarchist Festival 1st to Monday 4th May 2020, happening in May 2020, the decentralised model might make a small difference in taking the full focus off London and this one event.