One of the largest coal merchants in Dundee and still significant into the 1970’s at least, one of the roads in the old Caledonian shed was known as “Smith Hood “ as it was adjacent to their part of the yard.
They had an office in the town centre with a large model wagon in the window in full livery.
Could the NB have something to do with the North British railway? I know they had “Thirling” agreements with a number of collieries and coal merchants.