I saw YDX 3821 and 3838 in their last days of service in, I think, Nov 1980, when I was walking to school. These are my favourite buses.
I have some photos of York buses, which will need to be copied and downloaded, from 1979 -1981 era. These include certain Lodekkas, including interiors, and VRTs. As I was 10+ at the time, and they were taken on a cheap camera, they won't be great...but irreplaceable nonetheless. Any interest?