Four additional sleepers were purchased new in 1959. They were used with two CB&Q cars to protect the schedules of the NCL and Denver Zephyr as they swapped cars in Chicago. In addition eight more cars were purchased 2nd hand and carried the same name series. This would be the LOCH series.
New:
#325 Loch Sloy
#326 Loch Leven
#327 Loch Lomond
#328 Loch Ness
Used:
#329 Loch Tarbert ex-MP
#330 Loch Katrine ex-B&O
#331 Loch Long ex-B&O
#332 Loch Lochy ex-B&O
#333 Loch Tay ex-NYC
#334 Loch Rannoch ex-NYC
#335 Loch Arkaig ex-NYC
#336 Loch Awe ex-NYC
Why the Scottish names.... No idea.