These appear to be an advertisement for Carta Blanca beer. To my way of thinking, they are unusual too. Advertising items are usually good property as I'm sure these fall into that area. I don't know what they're worth or how rare they are, but I do know I wouldn't let them go for a song at a garage sale. Beer aficionados and advertising collectors would jump at the chance to own this piece of advertising. My .02 pesos...