When I was little (4 or 5 years old), my uncle had several sets of Lionel F3's, all Santa Fe. I always referred to them as "Santa Fe's" not F3's. I thought that Santa Fe was the only railroad that had these locomotives. Every other railroad was just a fantasy scheme. A Baltimore & Ohio F3 was a Baltimore & Ohio Santa Fe to me. I was devastated when I found out that other roads actually owned these units. I think I was more upset about the Santa Fe news than I was about the Santa Clause news.
Tom