Rusty - Ahh, yes. Rode a Burlington 4960 fantrip to Galesburg in Dec 1960, and, lo and behold, another O1a was getting new flues in the roundhouse. It's destination: lease to the B&S! Note: December 1960. !, and !!
Chip - Ah, yes, again. The WPB didn't want highly productive big locomotives like the Missabe Yellowstones sitting idle during the winter months of WW II, so some were sent to the Rio Grande and some to either the NP or GN (can't recall). One of the Rio Grande loaners, #224, rolled over on the Big Ten Curves, after losing her air. She survived, to return to ore train service and to pull one of the two last Yellowstone fantrips on the Missabe (July 1961). Had the good fortune to ride that trip and to ride the cab of 224, briefly, but it was stuffed full with about 15 other fans + railroad crew!
pfandprr - excellent reconaissance on the RF&P locomotives. Think the last batch of RF&P 4-8-4's lingered on to 1959, when they were scrapped.
Charlie - Yes, the C&O 0-8-0's were too good to scrap. Other well traveled locomotives were the Wabash 2-10-2's, which ended up on the MoPac and Chicago +Illinois Midland, but these were sales. An Ann Arbor 2-10-2 ended up on the KCS. The CB&Q leased to 2-10-2's and 4-8-2's to the C&S and the FW&D; of course they were subsidiaries, so they got 'em whether they liked it or not! And P&LE 2-8-4's to The Big Four.
Rich - And sister NKP #759 was leased for the Golden Spike Special in '69!
Firefighter - Was 614 retired as 611?
Thank you to all responders. Any tidbit about the WM 4-8-4's? They were thoroughly modern (built 1947), all roller bearing, quick turn-around locomotives, out of service by August 1954. Seems as though they would have been good lease candidates.
Funny thing, John W. Barriger, maverick RR CEO, suggested in the 1950's that American railroads invest in a small pool of diesels that could be loaned around to pick up the slack in motive power shortages. That was not done in that era, but steam locomotives got the job!