I think you  are talking about the louvered part of the vent that you can
use to adjust the airflow right/left and up/down.   Those might work fine,
if you can find some.  The old SL Mercedes had some too.  But they're not
expensive from Vintage Air...just go on line and order...no sweat.

But what to attach them to...... is the issue....plus getting the hoses to
them from the evaporator/fan unit.  Things are tight behind the dashboard
after the Behr unit goes in.  T

he louvers you mentioned are made to mount in a hole in the vertical face
of the dashboard.  I think the vents should be as high as possible and
there's no room to cut new holes in the dashboard, otherwise you could just
use another set of vents from a Vanagon.

That's why I was considering the PVC elbows.

Warren