dimensions aren't necessarily useful as effectively most of these cars were hand built.
Adjustments to panel gaps and fit was done with wooden blocks and leverage.
What's important is how square the suspension pick up points are to each other and the diagonal measurements of the subframes front to back.
If you have a nice flat garage floor then grab a plumb bob and some chalk so you can start scribing out points.
level the shell in both directions then start chalking off reference points on the floor.
Move the shell out the way and measure diagonally, and down the sides (essentially measuring a box with an x in it) if the diagonals match each other and the left and right lengths match eachother then you should be square.
measuring the subframes for square is much easier but essentially the same process. Could be beneficial to measure the subframes while bolted to the car.
I can't tell you how accurate the measurements should be, there was probably a, tolerance at the factory . Maybe one of the more seasoned blokes can help out.
I recently checked some subframes I picked up for square, they were pretty close given my craptacular measuring method (tape across the diagonals) so I called it good.
Remember, built with jigs and adjusted with blocks of wood. It's not uncommon to get different suspension settings left to right (expect infact).
https://www.google.com.au/search?ie=UTF ... vn_viCM%3Aplenty of information about.
