Don't know if anyone is still following this thread, but i used to be obsessed with this railway when i was about 12, which would have been 1981. I used to live on the estate. I used to treasure hunt it with my metal detector, and found a cast iron "beware of trains" warning sign close to where that carriage wreck is (between M5 and viaduct site).
An LMS telegraph insulator also. I located the refuse dump from either the station or the crossing cottage at holly hill. After they'd excavated the quarry behind the shopping centre, they used it as a rubbish tip. Dates of finds were around 1910 -1930 Which included a briarwood smoking pipe and several bottles (maybe the stationmasters pipe!) That u-tube vid of the railway is awesome! The particular crossing cottage in the video is the holly hill one. It was sited between the shopping centre and ormond road, next to the car park,right where that grassy area is now.