(The picture in the Facebook post has a slightly higher resolution, which is the only reason I'm embedding it rather than the Instagram post.)
I have all of the Kinks' albums up to The Village Green Preservation Society (from 1968). After that, I have only a couple, so I'm not very familiar with this era of the band. I think the keyboard player here is John Gosling.
This is the first picture I've seen of the Pianet's swell pedal being used.