Wil,
All the 356s and
early VWs have swing axles. The axle
rotates inside the axle tube. The axle boot (red arrow) allows
for the angular movement of the axle tube relative to the
transmission side cover. It doesn’t rotate.
"

"
© 1965; Elfrink, Henry;
Porsche Technical Manual.
The original equipment axle boots were not split and are
installed during the transmission assemble. Only replacement
boots were split.
I suppose there are later VWs with Lobro CV joints that may
have aftermarket (or even VW) split boots. I just haven’t
seen one. If there is a suitable split boot, we all should know.
I can see getting gas in “Last Chance” Nevada and smelling
CV grease on a heat exchanger.
Best,
Grady