I have one of these available "fitted with a clear lens", it is in fairly good condition.
As fitted to Gamecock, Grebe, Siskin, Bulldog, Snipe & many others.
Will exchange for WW1 instruments, compass, airframe parts, aero-engine parts, cockpit fittings, electrical switches etc. 1920's & 30's instruments, cockpit fittings, control fittings etc. Or sell depending on £ offer.
Cheer's.
Bob T.
sopysnipe@gmail.com07434448032 (UK).