Yup, I remember Bruce Latton, made me do steep turns at 50 ft over the sea, ON INSTRUMENTS!. Sure sharpened up my IF. Sadly Bruce died a year or so ago.
I never had any technical difficulties with the Gnat, but do remember one solo Hi Lo Hi to Scotland. I elected to continue over the Irish Sea, IMC at 250 ft hoping to break cloud. Must have screwed up my DR drift calculations as I broke cloud just abeam Blackpool Tower, only 20 miles off track. Would have been famous if I had hit it!