Weston Master Universal Exposure Meter Model 715 / S74: USA manufacture from 1939 and UK from 1951.
The U.K. manufactured model (left) and two variants of the U.S.A. model. Principle differences are the white meter face on the UK model, and a white, rather than silvered shutter speed ring in the dial. The two variants of the meter legend on the American model are shown.
The hinged baffle on the back of the Weston Master meter. When locked away from the lens, the meter operates in the low light level range.
The invercone attachment fitted over the meter cell. Also shown is a filter attachment for the cell.