I travelled around Europe a lot in the 60's mostly by thumb and seem to recall 127v in Paris, Luxembourg and Leningrad. The sockets were all 2 pin same spacing and same thickness as current CEE 7/16 plugs. I carried a homemade adapter consisting of a European 2 pin plug and UK BS546 2 pin socket for my shaver. The European plug had quite a thick case which stops it fitting in modern Schulko sockets.