"I know it's far too late to change it, but to be quite honest the combination of overhead shots and a lack of a horizon of any sort in the backdrop is really detracting from an otherwise amazing piece."
The whole project is/was a test piece to see if this scale/gauge combination works - as such most of the materials were scrounged or donated for free and this is why the size of the base and backboard was decided upon. If I was to build a proper working and landscaped model railway along similar lines, I would make a number of changes - a bigger (and curved back scene) being just one.
"Is it meant to be photographed/viewed at a lower angle than these in-progress shots?"
It is intended to be views at just below eye level.
Thank you for the comments.
Tony