GEC 5ft 80w fitting - with diffuser fitted

GEC 5ft 80w fitting, probably 1960's. I believe this is the predecessor to the 103 which itself is the predecessor to the Europa, so possibly this is a model 102 (just a guess)? Would love to find this in a catalogue if anyone has one.

Here you see it with it's original diffuser fitted. This is made from much thicker plastic than modern diffusers and the securing end caps are a neat design which are spring loaded and simply clip over the end of the spine & hold it in place securely.