Yes, now that I look closer at another wheel I have I see a 6 to the left of the valve stem, and a 7 underneath the valve stem on the right if I move it to one side with my finger. To the right of the 7 is the YJ stamp. Also, to the left of the 6 appears to be stamped K 1 9. The K 1 9 is very faint, almost unreadable.
Jimmy V.