Yes, they are stamped "L" or "R"..
I checked my panels again this evening and you are correct, they are stamped "L" and "R". I guess it helped knowing where to look. My good panels still have the original paint along with some other colors that made it a little hard to find. The stamping on the other two panels is very light and you could barely make out the stamping, even knowing where to look. One thing that I noticed is that the "L" is on the right side of the center hole and the "R" is on the left side of the center hole.
I am always learning something on this site.
Thanks
