Hey Jed! I didn't want to leave this thread hanging. Family commitments. Yeah, the nearly all the parts are new. I reused the usual parts like the headers and CPU, then pulled the 798 13600s. Although not likely relevant here, I used a NOS 4560D for IC27 (instead of a Tl072). Memory was also NOS and sourced from our group here.
I'll have mot time with the board today and report back. The problem must be staring me in the face.