Originally Posted by Bill Burk
The Weston Master model 715 would have been available at the time, and many of them are still working and accurate today.
I have one which reads within an f/stop of my other meters, and the point could be debated which meter is actually correct.
I have one of these, http://www.westonmeter.org.uk/650.htm which was given to me about 1974-5. It still works!