"…knowing him, and something of his deeds, it was impossible not to believe in greatness. In that square figure was housed a spirit of grandeur, and with his massive heroism went gentleness and modesty, even humility. He had no need to proclaim his virtue, for history would be his spokesman."
Eric Linklater on Wavell.
6B = Aircraft Navigation Equipment, Accessories and Spares
RAF Stores Prefixes - 5D/XXX etc.
Can't identify beyond. I agree it does look some form of winder. The RAF Museum at Hendon might have the full list.