Ex-Great Western Railway Collett '61xx' class 2-6-2 Tank No. 6148. Built at Swindon in January 1933 and withdrawn in September 1964.
We do not know (and may never know) the names of the Southall footplatemen proudly and happily seen with their steed in 1957. What we do know is that within a decade, '81C' will have closed to steam and magical sights like this will be consigned to history.