Last year's idea of alternating days of the week each month seemed to work quite well, so shall we pick a Monday in March and start from there? Maybe keep the British Museum as a backup plan just in case it rains on the day, but hopefully meet at Coram's for lunch and play?
So we can either go for earlier in the month (5th or 12th) or wait until a bit later (19th or 26th) although I know B&M has suggested a meet at the Sling Show on the 24th of March, so it might be better to avoid arranging another meet for that week!
Let me know what works for you

[edited to change thread title]