Posted By:
Al C.risafulliThe one with the Sweetman back is from the Sweetman set, and is not a W502. Not sure about what the blank backs could be, but it doesn't sound like a W502. There are several sets which use the same basic design that the W502s use; I don't know which one came first. 1927 York Caramel, maybe?
David Vargha wrote a great article on the 1928 ice cream cards - Yuengling's, Tharps, Sweetman and Harrington's - for SGC Collector that could help you identify what you have.
-Al
PS - the One Baggers are W502s. Looking to find them a new home?