That’s interesting as in Australia it would be a lorry. Maybe it was just a GWR thing to call their 4 wheel flat topped delivery wagons drays. A dray in Australia was a heavy duty 2 wheel cart with a low sided body and large wheels but no springs, used for earth moving in construction etc. Unless the lorry was owned by a brewery when it would be called a brewer’s dray.But if it was ex-NER it would be a lurry.
That really is an example of local nomenclature. Did the North Eastern Railway have a different diagram book for the parts of their railway outside Yorkshire who would have called a rulley something else, probably a lorry.
Well, I’ve learned something, I never knew there were 2 g’s in wagon!
Apparently it’s old English, that is if you believe any website beginning with wiki.