Realistically you don't care what those measurements are, I'll tell you why. First off, they were all different, these bodies weren't as precise as they are today, not by a long shot. Secondly how do you know the body that is being measured is right? How do you know the guy measuring it for you is using the same measure points as you are? You don't want to rely on some number someone gives you, you just don't.
It would be wonderful if this could be done, but realistically the number you would get is pretty much worthless.
This is what you want, you want to be sure it's square, measure to right to bottom left and then top left to bottom right to see if it's square. You want to put it where ever it makes those doors fit well, be damned the number someone could give you, make those doors fit well and that is what you go with.
Find "control points" that are consistant on both sides of the body. This isn't so easy with the older cars they didn't really have them as they do now. But find some places that are consistant, hinge mounting holes are a good spot, but others get a little harder. If you find somewhere like where two pieces of metal meet in a corner, be sure that you make a few measurements within that area on both sides to VERIFY that the point is consistant.
Here are a few measuring ideas used in late model cars.
And here is a "Basics of Basics" on using a tram gauge to measure. This all can be done with a measuring tape of course as long as there are no obstructions.