I was looking at an old episode of Heartbeat this morning and in one scene at the railway
station a large sign read "all tickets must be shewn" I thought that the last word should be spelt SHOWN so what is the correct spelling?
Yes, shewn is an archaic spelling of shown and in particular I think shew meant to show the validity of something. I don't remember it being around in the 1960s- more like 1900 I would have thought. But words and spellings do change- for example when I was at school the words TODAY and TOMORROW always had a hyphen in and kilogram was KILOGRAMME