Some might say that the Santa Fe F3 is the most famous engine in Lionel History. I just realized, though, that the most common Lionel scheme may not be prototypically correct. Here's two of my Lionel units:
Most common is the all-red nose. Only a few variations have had the yellow stripe up over the nose to the cab windows.
Note also the difference in the nose shield:
Catalogs from the 1950's clearly showed the all-red nose.
The only time I ever photographed a real AT&SF F unit was in Kansas City, June 1973. The locomotives were working for Amtrak.
I checked several of my reference books, and could not find a photo of an F unit with an all-red nose. All had the yellow stripe extended up to the cab windows.
I'm probably not the first to notice this, but I must admit it came as a bit of a shock. All these years I've been thinking that the Lionel units of the 50's were an accurate reflection of the real thing!