UR-CQD certainly passed over Biggin Hill around 1.30pm, clearly visible.
About half an hour later something with a big Lycoming passed a couple of miles to the south of me - high winged tail dragger flying slowly and quite tail low - think it was a Helio Courier but not sure and it didn't appear on any of the ADSB sites. Presumably G-BAGT if so, unless there are others in the UK.
Lots of light aircraft activity today before it's all stopped. Surrey Hills gliders and one of those Paramower things too...