At the time the lowest numbered WD 2-8-0 No 90009 (would that make it the oldest?) still in steam though officially withdrawn on this actual day and NER Q6 0-8-0 No 63395 at Sunderland South Dock shed on 1 September 1967.
Clearly the WD has seen the attention of enthusiast cleners including a red backed smokebox number, I doubt if anyone employed at Sunderland shed would be paid to clean or paint up engines by this date. 63395 is of course the lucky one that was preserved.

Photo: M.J. Fox / Rail Archive Stephenson