It looks like people are on the money with Oliver Ford Davies as Measter Cressen, but I was thinking Anthony (C-3PO) Daniels. He's got the Indiana Jones and Star Wars thing covered, but I'm not so sure about the rest.
The reason I think many people don't recognise Glover as Pycelle is that with the beard and his advancing age (76) he doesn't look like he used to. I really only remember him in Dr Who and For Your Eyes Only.