I’ve only ever seen the 2 pint oil bath filter like phak1 posted
Maybe in Canada it was standard equipment on all the trucks
And early trucks had a metal arm coming up from one head bolt to help hold the air filter which has a welded stud to bolt it to that arm(1950 model for sure)
By 1953 the 2 pint filter has the support stud removed and is fully supported on the carburetor.
-s
