A few years later, here is the update. The oil consumption was still there, so the new stem seals were not the panacea. I now know why. One of the kids hit something and put a hole in the pan. I now have a bottom end with more bearing material in the pan than around the crank main and rod journals, though the crank still turns. I found a running junkyard motor and later found that one cylinder did not leak down well. Oh well, two to make one.

Here is the takeaway: ALL 12 cylinders are missing crosshatch in rather large patches up, down, and around the bores. Inside bore gauge and mic showed 0.002x-0.003x piston to wall clearances yet we were able to slide a piston down the bore with a 0.004 slider gauge (no rings, of course).

M103 Bottom End Rebuild topic coming soon.