Don’t know if you guys boomarked this a while ago - I found it when cleaning up my bookmarks. It’s the photo archive of the Jackson & Sharp company now stored in the Delaware Punlic Archives:
There are quite a few plans and other interesting photos. I liked this one, labelled ‘Railroad Car - Railway Car Loading - Export’
You can download the originals from the archive.
I was wondering what was going on in the bottom right corner, and as the photo was scanned to nearly 6000 pixels wide, I took a look.
Widening it with Photoshop, I could just read “Steel Passenger Equipment” along the top of the sign.