Image via cartophilic-info-exch.
Snow White was included too, although I'm not sure how many she appeared in.
The chocolate bar and cards were promoted in conjunction with the Mickey Mouse Weekly, which featured a jokes and comics section called Wise Quacks (see an example in an earlier Archive entry). Kids who collected the entire series of cards could mail them in with return postage. The company would then post them back along with a free card album.
A couple of ads from the magazine...
See more cards and ads at Disneyville.