And of course, GM no longer owns EMD, it was sold to Caterpillar (their subsidiary Progress Rail).I highly recommend the current, quarterly edition of "Classic Trains" magazine.
It has an early history of the EMC corporation, which became the EMD div of GM, some of which appears to be paraphrased from founder Hal Hamilton himself.
I'll bet Robert B Claytor had his hand on one of those throttles.