I am curious as to when ice cooled reefers were completely replaced by mechanical refrigerator cars. On what railroad and on what route did they last run? The largest icing facility which I can recall was on the ACL at Waycross, GA. Reefers carrying Florida grown vegetables, citrus fruit and even cut gladiola flowers often ran in whole unit trains and were re-iced at Waycross for their trip to northern markets.
Early 1970s seems about right for the retirement of the ice reefers. I recall seeing a few around Sanford Fla on the Seaboard Coast Line in 1972. There was still an icehouse at Sanford,actually Rand Yard.