Thanks, Treadders! Ah, what a little gem she is! I think, the first 337 in the UK. There was an older 336 (fixed gear), but -CU's got to be one of world's oldest 337's still going.
The University use her for photo survey - nifty hole in the floor for the camera, with a little electric door to cover the aperture when the photo gear's not in. All mods done by Marshalls.
The guy that used to fly her until about 1982 was one of Europe's most experienced 337 jocks, he flew it from 1965.