This October '74 ad calls for SP and UP examples of the FP45, which Athearn did not produce. Athearn did stray from prototype and offered an Amtrak and B&O FP45. In strict terms, the Milwaukee Road example is not prototype. The Milwaukee's collection of five FP45's did not feature dynamic brakes. Thus, the Athearn 1974 issue FP45 is prototypically accurate only for the Santa Fe examples. Santa Fe rostered the majority of EMD's FP45 production, nine of the 14 built, and was the reported inspiration for the model. Illinois Central nearly got five FP45 diesels, but cancelled their order with EMD. Sadly, nobody has to date produced this almost IC FP45 in HO-scale. Given its minor position in EMD production, Athearn was surprisingly joined by not one but two competitors in offering a plastic 1/87th sized example. Lima of Italy made an FP45 that was marketed by AHM and Model Power in the U.S. Mehano of Yugoslavia built an FP45 that was in AHM's line and later in IHC's offerings. Thanks to its cowled body, the Athearn FP45 and its sister F45 both enjoy correct scale width hoods. Athearn practice of this time was to tool the hoods wider than scale to allow for the drive motors used. The FP45 design allowed both room for the drive and a correct width hood. Metal trucks are standard on examples of the FP45 from its mid '70s appearance into the '80s, when Athearn begins offering plastic truck sideframes for its models.

This October 1974 ad from Model Railroader shows the Amtrak SDP40F prototype promoting Athearn's coming Amtrak decorated FP45. The ad also mentions the coming SD9 and 57-foot Mechanical Reefer expected on hobby dealer shelves by Labor Day 1974. The Amtrak paint features the road's Phase I look and carried roadnumber 503. The Amtrak FP45 would be the only roadname added to the model's offerings, until the 1990s and the addition of the Santa Fe Superfleet dress.