Stripped the passenger side a little bit more and found a yellow "K" under the original black paint, directly on the metal. Wasn't seeing any of the other codes, which sounds consistent with SJ cars from this timeframe per previous posts, so didn't strip all the way.
Found a small 2" horizontal yellow line on the right side under the original black paint, but haven't stripped that side yet. Is there anything normally on that side under the original black paint? The line was exactly at the bottom of one of the brackets that supported the condenser of an A/C system, thus the two holes in the circle.