Got several responses.  Here is the just of what I know.

The old starter was in the van for 70-80K miles.
Guy who rebuilt starter is a local starter rebuilder.  He also did the
fresh rebuilt I installed.
Battery appears to be up to proper level.
Teeth on ring gear all appear to be in good condition.
Engine can be rotated to change ring gear position without any change in
starter action.
Starter removed appears to work properly on the bench using a jump-start
battery
All ground surfaces and battery contacts cleaned before reassembly on
trans.
Manual trans.
84GL Vanagon.
No apparent rounding or wear on either the new or old starter Bendix
gear teeth.
I did not try the new starter before installing it.
Both the new and old starters appear to run the motor but won't engage
the flywheel.
The van sat for about 4+ weeks while I was working on the exhaust
system.

Right off, the only thing I see right now is that something must be
inhibiting the Bendix from engaging the flywheel.

Still looking for ideas.

William