my only information is via the internet and a local hot rod expert from the 60's that said the boxes can be adjusted but only so far. and if too far the steering will get too tight, and at which point it needs to be replaced with a used one in better condition.
now i suppose that there are aftermarket rack and pinion setups or equivalents that would fix things but would involve some modifications and more work.
IME, i'm still trying to decide if i'm a victim of steering box/tierod/steering arm/king pin/ball joint wear or if the manual steering on a '41 with its enormous steering wheel just involves a lot more movement than that to which i am accustomed. ...i'm sure i've got suspension issues too!