Some good news now bad news - the 1997 documentary on the making of the album Moving Waves was briefly available on Youtube. The bad news for monoglot English speakers was that the documentary is in Dutch. However, as it was made up of performances and interviews with Mike Vernon and Jerry Boys there was quite a bit not in Dutch. Die hard fans might even have been able to work out what was being said in Dutch as Van Leer describes the writing of Hocus Pocus, perhaps or as Akkerman describes his early career and Havermans is asked about the bass parts! Anyway it is gone for now.
Looking at the music of Dutch rock band Focus, started in the late sixties by Thijs Van Leer (b /31/03/48) with Jan Akkerman (b 24/12/46). Van Leer still performs and records under the name today (official site here). Akkerman's site here.