PN,
In June 1968, I was in a Varsity that was ferrying a group of us from Binbrook back to Shawbury after we had delivered four Chipmunks for UBAS Summer Camp. We did an airways crossing en route. It sticks in my mind because of a minor disagreement about the time we entered the airway, between the radar controller (Midland Radar?) and the Varsity's navigator, who was using Gee for position fixing. I knew about Gee, but had no idea it was still being used.