Grunau Baby RAFGSA 373-BGA 1663

Grunau Baby 111c.
I know its a long shot, but has anybody got the log books of RAFGSA373-BGA1663.
This glider has been restored to fly by a group in Germany. But bacause it hasn’t any recorded history the German Authority’s will not let it fly.
The Grunau was built in Germany registered D-1090 in the 1950’s? Then to the RAF GSA 373, sold to the late Eric Rolfe. Then regestered BGA1663 in 1972. CMY.

Many thanks

Dave