Technically speaking, there wouldn't have been many (if any) cars with beer logos running between 1950 and 1970 due to the Interstate Commerce Commission restrictions on advertising on private owner cars that went into effect in the late 1930's. These removed from the United States the cars that Atlas, Micro-Trains and others have done. I am not sure that this applied to Canada but it wouldn't surprise me.
In addition, many beer companies found that a car advertising what was in it was a natural target for looters. This, for example, caused the St. Louis Refrigerator Car Company to stop putting anything on their cars. SLRC was and is owned by Anheuser-Busch (Budweiser).
That pretty much means you're free to "roll your own" which might be easier anyway... get a logo, print it on a decal, and decorate.