I believe it is mid-1940s Ford Transit bus - the rear-engined model 49-B, 50-B, 69-B or 79-B produced after 1939 (1944 to 1947):-
http://en.wikipedia.org/wiki/Ford_Tr...r-engine_model
It seems likely that this example has had replacement side-panels fitted - or, maybe, it was built as a motorhome using the Ford Transit chassis.
Other modifications would seem to include twin headlamps.
Original bodies were supplied and fitted by Union City Body Company.
http://www.trainweb.org/oldtimetrain...BL_buses_1.jpg
34 a 1944 Ford and 47 a 1947 Ford.
http://www.trainweb.org/oldtimetrain...BL/TTC_519.jpg
1944 Ford Transit signed INDUSTRIAL LOOP.
http://www.trainweb.org/oldtimetrain...BL_buses_4.jpg
Old Fords parked with rear engine compartment easily accessible to rob for parts.
Above photographs from:-
http://www.trainweb.org/oldtimetrain...nger_buses.htm
http://home.cc.umanitoba.ca/~wyatt/a...rd-cox1943.jpg