"are these cans in the photo Keely Cans? that you are referring to?"
Yes, those are Keeley cans. I have seen the spelling that I used in my post, without the final "e", but after some of the recent discussion I believe that it is correctly spelled, "Keeley".
I have several SP Caboose photos with the cans (in use) hung from the hooks, but have yet to see a photo of cans installed on a piece of rolling stock. The hooks were on large numbers of SP cars as well as PFE reefers, so the use of Keeley Cans must have proven worthy of the installations.
Thanks for sharing the photos.