M49C Tanker from Eastern Surplus and Equipment..
http://www.easternsurplus.net/408.html
described as:
M49C Tanker, 2 1/2 ton chassis, 1200 gallon capacity, Honda 18 hp electric start pump, excellent tires, Turbo diesel, Hard top, cab heat, winch, electric hose reel on side, siren, light bar...