Weston Master III Universal Exposure Meter Model 737 / S141.3: 1956, USA and UK manufacture. Brushed steel cased USA meter (left), the rare red dial UK model (centre) and standard glossy black enamelled model (right).
One option for fitted cases for this series of meters is shown here. The back section of this ever-ready case has a recessed compartment to house the invercone and filter for high light levels. The Master IV and subsequent Masters had a redesigned perspex invercone which was protected in a separate 'satchel' type leather case.