The model is based on one design of GA reefer, which was first installed in 1937. The CRLX 5501-6250 series, which is one scheme that the Rapido reefer represents, is in actuality a completely different design as Roger says.
If it is true that the 1501-series reefers were rebuilt from older CRLX cars, then the Rapido car is a foobie for CRLX in the absence of further information.
One of the issues that I've seen with the Rapido reefers' reception is that some high-profile modelers have asserted their accuracy for schemes like Swift, WCLX, ARLX, and CRLX when in reality those are foobie schemes. Reefers with those reporting marks were of different designs (especially WCLX), but I have seen very few modelers acknowledge this.
The Rapido reefers fill a need but are not sufficient to model a typical block of meat reefers representing a variety of meat packers.