Author: Priest, Cinthia, D.Pharm.
Titles & Dates:
The Santa Fe Diesel, Volume I: Dieselization to 1960.
The Union Pacific Diesel, Volume I: Dieselization to 1959.
Kansas City: Paired Rail Publications, 1998/1999, respectively.
Both these volumes cite GP-7s with steam generators in the short hood. In UP case, they may well have been factory originals, in AT&SF case, they were retrofits from FT units.
Hope this helps, John
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The City of Saint Louis (UP, 1967) is still my standard for passenger operations