All the original spray paint cans were shaped like that. The top was actually concave so in order to spray you would have to hold the can at a 45º angle. They were only made for a very brief time I would say 1949-1951 maybe a little longer. Lots of ads I see by 1951 had already changed the can style, to a slightly more modern look. I only know of a handful of paint cans that were made like this. You mostly see them as bug sprays. Other household products were also available. I will try and get some pictures of the random cans I have.
**** VINTAGE OLD USED UNUSED AEROSOL SPRAY PAINT CANS WANTED****