Gilbert,
I was thinking of the large number that were shedded at 33A Plaistow &33B Tilbury during 1958. I am guessing they were shopped at Doncaster, but I am not certain. However if I am right you could easily find a Path for a Light Engine cos you know it makes sense.
Regards,Del Boy.
PS Is that Old Duck from Retford alright I don't think we have heard from him for a while.