I'm sure I remember someone from that era telling me that the Lightning was a good lead-in trainer for the Gnat...
Well the avionics were the same except that the Gnat had no auto throttle and FCS / autostab (IFIS instead of the Lightnings IFICS) . during my 18 months tech training at Cosford in the 80's I had the joy of working on an ex Red Arrows airframe. Managed to drop a fuse down the back of the front seat. No amount of fiddling with endoscopic wiggly tools would recover it. The riggers and the plumbers were pleased
S