Hi Dave,
All your (and your dad's) photos are wonderful, but those taken in the late 1960s and featuring AC electrics are just beyond compare. J1818 (already commented upon above) includes a Fruit D a part of the partially fitted freight. Presumably with the rather dodgy riding quality of those sand hoppers, it was quite severely limited in speed? I reckon that J0832 (the AM4/AM10 combination) must be near unique.
Thanks again,
Bill