In 1919 the Federal Trade Commission forced the breakup of the Armour Refrigerator Line due to unfair competition. As a result, Fruit Growers Express was incorporated in Delaware on March 18, 1920 -- based out of Washington, D.C. -- to provide a shared reefer pool for the benefit of the ACL, B&O, PRR and Southern Railroads. Additional railroads later joined -- New Haven and N&W (1920), L&N and FEC (1923), C&O (1927), NYO&J (1931), and Pere Marquette (1940). (This list may not be all-inclusive.)
In 1926 the PRR sells 2,676 class RF 36' reefers to the FGE.
In Feb. 1928 FGE forms the National Car Company as a subsidiary to serve the meat reefer market. Initial customers include Kahns, Rath, and Oscar Meyer.
Painting & Lettering
Rick Tipton writes "FGE's distinctive Block Gothic black lettering on a yellow carside with red-brown roof and ends has been in use at least since 1929. As Gregg Mahlkov points out, these cars were painted "VENTILATOR AND REFRIGERATOR" (stacked on three lines) from that date to at least 1950, and may have been seen as late as 1959. By 1952, the legend became "REFRIGERATOR" ("MECHANICAL REFRIGERATOR" on one or two lines where appropriate). A minor change in 1956 eliminated the 1-inch "AAR bars" above and below the reporting marks. In 1969, the legend became "Fruit Growers Express/for/Greater/Efficiency" (four lines), but this was applied only to 50+ foot mechanical reefers. When needed during harvests, steel and even wood-sheathed ice reefers continued to run in the 1952 and 1956 paint schemes into the early 1970's."
"FGEX was the most-used reporting mark, but others included FGCX (mechanical), FHIX (documented between 1951 and 1961), and FOBX (with special overhead ice bins and 10 roof hatches). FGE also was the reefer contract operator for Western Fruit Express (WFEX, see below) and Burlington Refrigerator Express (BREX). In addition, FGE operated meat reefers under the name National Car Company, with reporting marks including MNX. These other three fleets used elements of the FGE image, but lettering often departed some (or a lot) from FGE standard."
"Starting in the 1950's, FGE began to build 40' and 50' insulated box cars in its shops for lease to its member railroads; these cars carried a wide variety of reporting marks (including PRR and PC) and are sometimes referred to as "grocery cars". The AAR Mechanical Code for these cars is typically RBL ("bunkerless refrigerator car") or XMI/XLI ("insulated boxcar"). While lacking refrigerating equipment, these cars are well-enough insulated to keep loads cool through days of warm weather. These cars use some parts of the FGE image, their lettering has its own peculiarities -- beware of confusing FGE refrigerators with their insulated boxcar brethren".
Martin McGuirk writes "Also, an interesting note that several of the cars were obviously in assigned service -- I have pics of several cars with routing instructions stenciled in a fairly large rectangle on the left side of the car between the reporting marks and the end grabs. One car, FGE 37363 has a route box that is very readable in the photo and reads (in the following format):
When Empty Return To
Greenville N J
Via Service Route"
The Steam Era Freight Cars web site indicates that "Aluminum-painted roofs appeared on some FGE cars during the 1940s and were common by 1954." However, Martin McGuirk counters "while there are certainly a few of the cars in our photo files (about 300 pics of FGE/WFE cars) very fewer -- less than 10 -- show silver roofs clearly. Some are questionable but I'd hesitate to say that 'silver roofs were commonplace' by 1955. The evidence I've seen in these photos, and all the pics I have of these cars on Central Vermont trains, simply indicates otherwise, at least before 1957 or so. In short, silver roofs in 1954 on FGE cars seem to be the exception, not the rule.
HO Scale Models
FGE Wood Refrigerator Car
Prior to initial release, Martin McGuirk [then of InterMountain] wrote "Our FGE reefer is a rebuilt car, by the way, which carries its service life well into the late 1960s. Our model features the optional 'sill mounted' Preco fan -- not on these first few runs but will be on later runs -- and the geared brakewheel end -- some of the rebuilds had vertical brake staffs an option we're including on the HO model but not on the N scale one. Other features include a Hutchins roof, with the roof hatch guards molded in place. If you see a photo of a FGE car running with the hatches open it's rare."
InterMountain #47706 - Ventilator/Refrigerator [as late as 1959]
InterMountain #47701 - Refrigerator [starting 1952]
InterMountain #47720 - FGE - New York, New Haven & Hartford
InterMountain #47731 - FGE - PRR 
InterMountain #47732 - FDEX - Double Deck