Brad, I'm going to say that it will be impossible to identify the
keyboard used from a photo. The issue is that all sorts of computer
equipment used gray key bodies with white letters.
For example, here's a Control DD60 console display unit:
https://en.wikipedia.org/wiki/CDC_6000_series#/media/File:CDC_6600_console.JPG
GRI (George Risk Industries) probably made a jillion gray-keyed
keyboards for various manufacturers. IBM used gray keys, Univac used
gray keys, CDC used gray keys...it's pretty much impossible to say.
--Chuck
