Sorry NickL, I see that you did.
It is difficult to do with the accuracy we need as points to be measured are not on the same plane or otherwise obstructed. I was hoping someone might have a trick.
I did my best to find the center on the flywheel and scribe a line as per your suggestion. The flywheel bolts seem to be in the center as expected.
I then slid a piece of paper in the center joint to see where it meets my scribe line.
It appears to be right on center with my .086 shim stack on the drive side.
On further thought, this makes sense as MarkB pointed out above that the drive side bearing on the late case has been shifted outward.
The late crank has a thicker counterweight on this side that makes up the distance that my early crank lacks.
For some reason I was making an assumption that my shim stack was excessive and the slack was on the timing side at the thrust washer.
Unless someone points out that I'm off base here, I'm going to run with it. Whew!
Thank you to those that helped me hash this out and I hope it was not too tiresome.