On 05/09/2016 11:34, wrote:
Here's a Twin Rover ticket from 1967:

http://www.yellins.co.uk/transporthi.../redrover.html

My recollection is that they weren't valid in the morning peak.

I don't recall.

But they weren't valid north of Rickmansworth on the Met.

(Since we always boarded at Watford Junction or Croxley, depending on
which grandparents I was with at the time, I can't remember whether it
was valid at Ricky itself.)