Phil Wood specifies a tight tolerance press fit between the axle and bearing ID,
so they can be pressed out and changed, ..

have you an arbor press to remove that axle?

some designs put a shoulder on the axle, some don't?
I have no Idea about the way VO's source contractors put their BB assemblies together
never owning one.. ,
You may be able to rethread the axle oversize,
if you have the right tap and a replacement bolt.
OTOH,

You may be stuck with just buying another whole unit.
As there is no universal common cartridge bearing BB spindle.

do they offer a cut away diagram as to how they were made..
and a link for the curious