I can date it a little more precisely than I previously thought. Bert had delivered a public lecture on whaling songs, I think, and a few of us went for a meal with him afterwards. This was immediately after Charles Parker had been made redundant from the BBC and the matter of his redundancy came up in the conversation. As far as I can remember, that would have been late 1972, and a thirteen part series would have started at the beginning of one of the seasonal schedules. EG., early September. I also recall that the series had been running for a number of weeks then, so I'd guess the conversation would have taken place about October or November. Whatever, it was certainly a dirty night. But can anyone get it closer than that?