There was a whole range of these vehicles. The F45, F55, F65, F75 and F76 (six cylinder). Recently had this matter with a Russian bus puzzle in which the last of the three options was the correct one. Lets see if Murphy's law applies again here.
1st attempt: H55
By the way I really like the entry hatch in the passenger's side roof of the cabin. Convenient way to enter the cabin ;-)