...to see that the registrar in tomorrow's SJA episode is played by Zienia Merton, who was Ping-Cho in the 1964 Doctor Who story Marco Polo. I think this must give her the record for greatest elapsed time between her earliest and most recent appearance in Doctor Who and its spinoffs - apparently she is in Friday's episode as well so that will be 45 years, 8 months and 7 days since 22 February 1964. (Of course, that is counting televised versions only - Carole Anne Ford is in a Big Finish audio release as Susan later this year, 46 years on.)
