Are we talking about the late seventies here? I think he's a throwback from several centuries before that, but in the 1970s he would still be hanging on to that post-Second World War look, wouldn't he? Cardigans probably, jackets.

In the summer I think he wears a black one incongruously, because it attracts more heat, but it would be light-weight material. He probably wears a panama hat too, and he would walk around Cambridge I think maybe with a stick, but of course he'd look best in a mortar board.