Old Ball Perfect Mason Jars

I have two of these jars in excellent condition. The front says Ball Perfect Mason in solid block letters and under that is a 13 on one and a 4 on the other. The back says made in U.S.A. The one with 13 on it has a 13A on the bottom and the other has a 4B on the bottom. They are ribbed, square, and both are screw caps. Jars measure 5.25" x 3". Just need help dating. Thank you.