Amongst my personal collection of items that I consider to be 'collectible' are these two Jantzen logo's, most likely used in the 1940s in advertising. Back in the day, these would have been used by typesetters, so when stamped would give the flipped image.
I've flipped the image so you can get a better look of the typeface.
Another piece I happen to have as part of my personal Jantzen collectibles is this pin from the same time frame.
I guess what I have now is a collection because it's more than two. Oh and if you haven't seen all my Jantzen swimwear you really should check out my store Glamoursurf!