I know the photo you mean and its actually from "The Greatest Show in the Galaxy", during the asbestos scare that nearly closed down production, as for Troughton he's spawned a family of actors, from what i know two sons and two grandsons are both actors, hell i loved Sam Troughton in Chernoybl, i was shocked when i realised it was him.
and for the overlap the ones that come to mind are, Carmen Silvera appeared in two stories "The Celestial Toymaker" and "Invasion of the DInosaurs" before becoming Edith Atrois (that stupid woman), Hillairy Minister appeared as Marrat in "Planet of the Daleks" before becoming a nameless Thal in "Genesis of the Daleks" which also featured Guy Siner as Ravon, the two would become General Von Klinkerhoffen and Lieutenant Gruber respectively, John D.collins appeared in "Arc of Infinity" around the same time he was cast as Fairfax, David Rowlands who played the Doctor in the final few series of Allo Allo was Bisham in "The Sun Makers", Richard Gibson did two audio stoires for Big finish those being "Flip Flop" and "Warlocks cross" and i just found out Arthur Bostrum was in "Scarday Cat" what a good Moaning that was to find out.