The Facebook link I had above is to the group looking after the remaining APT. Some nice photos on there. Sadly a lot of filler in an attempt to restore it cosmetically.
Have you thought about offering your services to the missenden college for railway modelling ?
People talk about soldering and electronics being a dark art. But people also shy away from modifying RTR models and cutting and shutting.
The course could go through the research, planning stage, tools and materials. Then the practice of turning two Triang/Hornby MK1 BSKs into a BG and a SK!
http://missendenrailwaymodellers.org.uk