I do have some info on Cumbres, I was digging some of it out for Frank of the Friends. Will post some of the info at a later date.
Yes there was a log loading operation on the extended tail of the wye.
The Car Inspector or Air Inspector checked the brakes on the Westbounds, not sure if he set up the retainers or if the train crews did that, also not sure if he did any repair work on the cars at Cumbres or of when that job was abolished.
The gas station and a couple of cabins were owned by the Livelys- some info in the Chams Cumbres & A Little Chilli book.