Missing Stuka Relic

A family friend has asked me for help in tracing a relic from a Stuka that was shot down at South Mundham near Tangmere on 16 August 1940. The photo can be found in several Battle of Britain books. The relic is the starting crank handle (I didn’t know they flew with them fitted but I’m no expert) which was removed by our friend’s father at the time. It was loaned to the Tangmere museum in the 1980s but it’s not there now and the present curator has no record of it. Apparently quite a lot of this sort of material was removed from the museum in the mid 90s so it’s possible that the handle went at the same time. Grateful for any information that can help him get the item back.