FWIW, other Winchester literature contemporary with that ad recommends ordinary folks do NOT attempt reloading with smokeless powder. I've seen it, though I have no way of putting on the web. (sorry)
Smokeless, at that time was new, complex, and not at all safe if done wrong (and in those days, doing it wrong was easy). Winchester was fine with everyone reloading with black powder, and made the .32 Special to do just that.
Of course, over time, Winchester became an advocate, and major supplier of smokeless powder reloading components, but back in the early days, it was still something akin to voodoo, that "only" the factories knew how to do right.
Deerhunt, pick up a reloading manual, old ones can be found real cheap (the data isn't very valid, due to changes in powders, over the years) Speer, Hornady, and several others have descriptions of the cartridges and brief histories, which you will find useful.
Welcome to TFL, and welcome to the world of shooting sports!