Lovely layout, and one of particular interest as I was born and brought up in Hemyock.
However, as I was only 3 when the branch closed I'm afraid I'll be of little use to you regarding the history and finer details given the time period you're modelling, although I do remember seeing trains on the branch and my earliest memory is that of watching a class25 shunt the tanks.
One thing that does occur to me, although I've no idea if it is of any use, is that just to the east of the road bridge in the River Culm itself was a large hole about 20' deep. there was much talk in the village about its existence as no-one knew it was there. It was only discovered when a local driving home one night in the late '70's suffered an error of judgement that saw him driving off the road and into the river. He managed to get out straight away, but his car slowly sank out of view. As the river was only a few feet deep (unless the spring floodwater was present) through the area no-one believed his story and it was only finally proved correct when a diver was sent down by his insurance firm. The hole was about 6' wide by 5' across and the perfect size to hide his car completely - it was pure chance that he managed to crash into the only part of the river that would hide his car. I'll have a word with my parents to see if they remember any further details.
