There are no standards of sizes between manufacturers so two items with the same U.S. size will not actually have the same dimensions. Vintage clothing sizes can't be compared to more modern sizes since people on average had a smaller physical size. Laying clothing flat and listing dimensions is a waste of time as it does not account for the depth of the person who will be wearing the item. Does a tailor lay your clothing out flat on table to alter it or do they have you put it on?