LOL. Forgot this dumb question was still out there. Anyway, one of the PO had put a glob of jb weld or something on the front vent hole (67 dual barrel MC) within the front barrel of the MC. This was compromising the re-circulation of the brake fluid going to the rear. I'm not sure the reasoning for this but for future readers, I believe it was the PO attempt to modify fluid pressure similar to what a proportioning valve would do. As for now, putty stuff gone.
Added to the above, the truck sat for years even though restored. I assume moisture, etc. Hence brownish fluid.
So there. I finally got a response. Unfortunately I think Im talking to myself.