Anyway, TrainMan has shared with me some truly bizarre (and really quite geaky facts). I have shared some of them below for your delight and delectation:
1) There is a branch line south of Oxford.... This is (apparantly) the Cowley Works line built in 1972. (Honestly this is what TrainMan told me).
2) The signs at Kingham and Charlbury stations used to be painted different colours - it apparantly used to be black on white rather than white on black as illustrated below:
This level of observation is a little beyond me.