4681 / 5000
"The last day of official operations on the Cromford and High Peak line, Sunday,30th April 1967, was marked by scenes that beggar description ......"
The rest of the two pages devoted to that day's events are revealing as there is a picture of 68012 and 68006 with the SLS headboard clearly visible and the text states that the first run of the day, there were three in total, was chartered by the SLS (Midland Area).
The puzzle regarding 68012 wearing a 50A (York) shed plate on its smokebox door is partly answered by Peter with this quote from the June 1967 Railway Observer: "68012 commenced the operations sporting a 50A shed plate, but this had been removed by the afternoon.". So, now we've narrowed down the time frame for this shot to the morning of 30/4/67 but why the 50A plate in the first place?