2planks/57mm
You may be right. I seem to remember my groundschool instructors were G+10, T+8, Gordon Allen and Gay Horning and I'm sure they called them Pilots' Demand Levers or PDLs for short. This was the rig that they used to teach us with:
These are now in the Tattershall Thorpe - Thorpe Camp Visitors' Centre:
http://thorpecamp.wixsite.com/visitorscentre
Well worth a visit for Tornado F3 memorabilia and other Coningsby/Woodhall Spa stuff.
LJ