OK, I can't just stick a pile of kit bits together. I've got to fiddle with, and hopefully improve, them.
Looking at the signal cabin, the first thing I spotted was that the real windows open by sliding. One set of panes is set back from the others but on the kit, they are all in one plane.
Not a problem. Running a sharp knife around the end frame is easy thanks to the depression for it to follow. The end 4 panes are removed and then fixed back a millimetre with lashings of plastic solvent. The middle bar is deepened with microstrip at the same time.
Needless to say, this doesn't show up in the photo, but trust me, it makes a difference.
The other tweak takes place on the door where instead of a handle, we have a little lump. Hardly surprising, moulding a proper handle would be impossible and an separate part would be tiny.
On my workbench there is a pot of track pins so after drilling through the lump, a pin was forced through the hole (more lashings of plastic solvent 'cos I didn't drill a bit enough hole) and trimmed inside the door.
Another tiny modification but on a little building, worth it to my eyes. Simple too.