There's also
Locophotos.com. The same login will get you into both sites. Both sites are very useful for certain information, but aren't much use for detail photos. The goal of both sites is to show the classic 3/4 shots or full side shots, rather than artsy or nuts and bolts type photos. However, the information associated with each photo is often comprehensive, so very useful for things like identifying builders, or dates, or some dimensions. I treat both sites as additional resources in the arsenal, rather than the end all for research.
I edited your photo, for what it's worth, which isn't much.
View attachment 157967
Freight Cars Illustrated was a collaboration between three guys that did railroad oriented research. One was Darrell Sawyer, another was Eric Neubauer, and the third name escapes me. It may have been James Kincaid. Anyway, they collectively produced the FCIX series of books and spec sheets, but in some cases also offered their own research products. Sometime ago, I purchased some books from Eric Neubauer, two of which combined detail Gunderson and FMC railcar production from the beginning through 2009. The other two books deal with ACF Centerflow covered hoppers and centerbeam flatcars. I would consider any of them to be fantastic resources. Unfortunately, Eric has apparently also stopped publishing his railroad research content, his
website still exists but doesn't have any content at all. I wish I had bought other books at the time.
View attachment 157975
View attachment 157976
The Rail Model Journal mags are supposed to be legitimately archived on the Trainlife website, along with several other now defunct modeling magazines. It's a nice idea, but unfortunately the website has often failed to work correctly, resulting in broken links or instances where only certain pages of a magazine would display. Issues had been addressed, but seem to be back in force again at the moment. I'm sure you could find issues available for sale, but it seems a shame to bother buying them when you can download them for free instead.
Gp38-2, the sub-base doors shouldn't split at the leading edge of the cab on the left side. The gap should be further back, lengthening the front battery box and shortening the rear box. That's a dash 2 characteristic. Photos that I see on RRpicturearchives.net show both classes of SP gp38-2's with the dash 2 configuration (
4802 and
170). Also, the ex-L&N units appear to be after phase 1a, as the radiator intake screen is a single block rather than split, and the fans are close together. Easy enough to fix that with a new etch fan hatch and hole location.
On L window replacement, I don't know much but have to agree that the new engineer's window is in line with the center windows. It only makes sense really.
This photo of 4806 shows the condition well enough I think. Looking at the catalog specs and the diagrams, I also agree that most likely the replacement horizontal portion was one of the extended windows. EMD apparently offered an extended window that was about 5" wider than the standard. Also, it looks like the standard configuration used the same size glass for all six fixed cab windows, including the door. It's interesting that there are three different sizes of "L" shaped windows.
View attachment 157977
View attachment 157978
Hope that helps in some way.
Jim
. Forget the rest of the stuff 
mode 