Enjoy Coke Enjoy Coca-Cola on Libbey glasses

I have 6 Enjoy Coke on one side and Enjoy Coca-Cola on the other side on clear glass bell shaped or flared out Libbey glasses. They have a curtisive L in the middle. Dimensions are 3" top dia. x 2" bottom dia. x 6" tall. I filled one up to the rim with 1 1/2 cups which is 12 oz. When I see Enjoy Coke on one side and Enjoy Coca-Cola on the other side, I think I found them. I thought they were 1970s. However, there's have an S on the side of the bottom of the glass rather than a curtisive L in the middle on their bottoms of the glasses like this one I found on ebay who put 1970s and Libbey in the title only to describe that he assumes the information and there is an S on the side of the bottom of the glass on the picture as follows:
Coke COCA-COLA 3 Vintage 1970'S LIBBEY Glass glasses bell shape Enjoy Coke! | eBay
I hope someone can unconfuse me. I would like some assistance in determining the decade Enjoy Coke on one side and Enjoy Coca-Cola on the other side on Libbey glasses came about? Thank you. Rob