I forgot to mention in the last post that another unusual aspect to coaches 284, 306, and 320 is that electric lights were addded to these cars so they could be so supplied while coupled in the consist of the San Juan between Antonito and Alamosa. The conduit is still there on all three cars, and either had to divert around or run between the vents for the oil lights. I believe these were the only vestibule coaches with electric lights on the roster.
Naturally, on the mixed consist south of Antonito, or in other service, the oil lights were used as needed.