Also at BHX BSR operated an HS125, the registration of which escapes me at the moment.
G-ASSM.
Standard Telephones and Cables - DC-3 G-AJRY
Ferranti - Heron G-ASCX,G-APMV
Dowty - Dove G-AVHV
British Steel - Dove G-AOFI
Rolls Electromatic - Dove G-AMXW
Leyland Motor Corporation - Dove G-APVX
BICC - Dove G-ARYM
Scottish Aviation - Dove G-AMFU
Hawker Siddeley - HS125 G-ASEC
David Brown - Dove G-ARDH
Standard Telephones and Cables - DC-3 G-AJRY
Plus most avionics companies - Marconi, Ecko Electronics, Decca, etc operated there own aircraft.