What do you mean too tall......
.... having been too tall for the Gnat then too tall for the Hunter how did he fit into a GR3? The last section of the video with him stting in the cockpit gives the impression that with a helmet on he'd have a problem closing the canopy (unless the seat could lowered by a lot) I did once sit in a GR3 prior to them departing on the northbound route to one of the "Flags" and thinking to myself as I looked at the space available "Sooner you than me matey, where will I get cup of tea?"
The Ancient Mariner