I believe there were 60 old cars in all, half motors and half trailers for the 2-car sets, numbered 1 to 60 in an extremely random manner between the two types which probably reflected the sequence in which they were converted from cable haulage at electrification. That gave 30 trains, 15 for each circle. If only 8 on each circle were needed that would be almost 100% provision of spares.
I also seem to recall in more recent times that the trains were painted the same red on all sides, the old accounts of them being painted black, or not painted at all, on the offside, being something from the past. If you are going to paint, it doesn't really matter what colour is chosen. Of course, the transfers etc were not applied to the offside.
Trains were placed alternately on one track and then the other to equalise flange wear, being swung round appropriately by the hoist. This is shown in the video described above, with sections on YouTube
although I think a more atmospheric film is this one
I also seem to recall in more recent times that the trains were painted the same red on all sides, the old accounts of them being painted black, or not painted at all, on the offside, being something from the past. If you are going to paint, it doesn't really matter what colour is chosen. Of course, the transfers etc were not applied to the offside.
Trains were placed alternately on one track and then the other to equalise flange wear, being swung round appropriately by the hoist. This is shown in the video described above, with sections on YouTube