Kev:
You're right, I couldn't pass this one up.
I looked again at my old B&W photos from '66, '67, and '68.
In '67, the water fill pipes had not been added to any of the wood coaches in my photos, and the storage boxes under the San Juan Cars are still there, but I think they were gone in '68. I'll have to look at my slides, wherever they are...
I see in the Grandt book that #350 did have the water fill piping in '67, so they must have at least begun the additions in that year. I don't find any trace of them on any wood cars until '67. I'm sure #'s 284, 306 and 320 never got them, and they were retired in '66.
As to the water fill pipes on the steel coaches, I think they may have been built that way. They were there in '64, according to the Grandt book Vol. 2.
Mike