There is not a whole lot of info available on the EMD FT, errr Model F, let alone specifically on the 103/103A Demonstrator. I have collected bits and pieces over time.
The most info I have is found in the book, The Revolutionary Diesel: EMC’s FT (Diesel Era, 1996, softbound 130 pages).
I find this a very informative and entertaining read. I have re-read it numerous times and it never gets old. EMC 103/103A is covered, although not as much as I would like. Then all of the FT users (many written by their respective historical society) are covered alphabetically from the AT&SF to WP (with roster info for each), a section on the restored FT 103, and a section on identifying dynamic brake phases. Many good B&W photographs, colour on the covers.
I found the following recently on e-bay: Instruction Manual for the Operation of Railway Equipment : GENERAL MOTORS LOCOMOTIVES. It is a factory Model F operator’s manual, although it is not titled as such. In fact, Model F or FT is not used anywhere in this June 1944 publication.
It includes some interesting interior photographs, locomotive and systems diagrams (many as fold-out pages), as well as operation info. My copy is in great condition, especially considering that it is 72 years old. The proceeds from this purchase went to a good cause in supporting Oregon Rail Heritage Foundation (ORHF).
Early Diesel Daze: 1935-1953 (The Chief Way Reference Series, John McCall, Kachina Press, 1980). This fine book details the early Santa Fe diesels in a chronological format. It has a small section on the 103/103A (it was tested on the Santa Fe in January/February 1940) with photos and info on pages 94 & 95. For me, another great read.
FT Tidbit: For those who find such things of interest…in the Diesel Era book noted above, the B&O section quotes a 1942 Instruction Manual as stating “the sections with cabs will be known as first sections, those without as second sections.” However, my June 1944 Instruction Manual states, in the very second sentence of the entire book, “The units with the cab will be known as ‘A’ units, those without the cab as ‘B’ units.” It seems that EMD’s thinking had changed during production.