Western Fruit Express was originally affiliated with the Great Northern.
CB&Q had its own affiliate, the Burlington Refrigerator Express.
Fruit Growers Express had a lot of “owners” back in the day: SAL, ACL, C&O, B&O, L&N, MON, C&EI, CRR, A&WP, FEC, SOU, N&W, PRR, and WP are the ones I can think of off the top of my head. Most of them are now components of CSX or NS. Eric, I think that FGE, if it exists at all any more, is now a subsidiary of CSX.
It should be pointed out that Burlington Refrigerator Express, Western Fruit Express, and Fruit Growers Express had some sort of relationship with each other, too–all three of them seemed to have the same corporate headquarters in Washington, D.C.
American Refrigerator Transit Company, as Eric mentioned, was jointly operated by Missouri Pacific and Wabash. I’m pretty sure Texas & Pacific came on board, possibly as an affiliate of MP.
The North Western Refrigerator Line was affiliated with guess who–and the Western Refrigerator Line was operated by the Green Bay & Western.
Merchants Despatch Transportation Company was owned primarily by the New York Central, but somehow wound up with cars lettered for IC, GM&O, and the Lackawanna as well.
I’m not sure what the relationship was between the Milwaukee Road and Union Refrigerator Transit Company, but there were a lot of URTX refrigerator cars with MILW markings. There were also series of URTX cars with M&STL and Soo Line markings.
Railroads that operated their own refrigerator cars in relatively recent times include NP, SLSF, BAR, MEC, EL, RDG, SOO, MILW, CNW. These are just the ones that had mechanical reefers–just about everyone had RBL-type cars. In earlier days, there were ice-bunker or brine-tank reefers with C&O and GTW reporting marks.
I’m sure that someone will be able to correct and/or comment on the actual ownership of some of these cars.