The problem with trying to calculate all this based on dimensions taken from a book or manual is that the published figures bear little relation to reality. At best they are purely nominal, not actual. If you doubt this, gather up a wide variety of cases from various lots of 9mm Largo, .38 ACP, .38 Super and 9mm Steyr and measure them with a micrometer. You'll find more variation between different lots of 9mm Largo from different factories than the difference between 9mm Largo and 9mm Steyr. And, except for the larger semi-rim, the same is true when Largo is compared to the .38s. Then make Cerrosafe castings of some sample chambers, and discover what an irreconcilable puzzle you wind up with.
In the end, the minor dimensional differences don't really matter. The important thing is that, after re-sizing, the cartridges will feed smoothly and without binding in the particular chamber you plan to shoot them in, and that the rim is small enough to fit in the slide face counterbore, and that everything is sufficiently concentric that when the cartridge is chambered, the breech will close comfortably in a blowback like the Astra 400, or lock up correctly in a Star. Then select the lightest load that will reliably function the gun. These guns are old-timers; give them something soft that their old teeth can chew.