The top one dates from late 1930s, the chassis is a 3 & a quarter ton BROCKHOUSE with torsion bar suspension, the tank is by Butterfield the pump gear by ZWICKY, powered by a LISTER 3hp petrol engine. Initially for petrol , then some used for aviation lubricating oil, and water -methanol. The above is definately an early example as the torsion bar suspension was changed to leaf spring in about 1940.
Any other shots of the second one please ??