Thanks for all the help volks!
I finally figured out why my "new" Tach wasn't working.  All the hook ups
were correct but the multipoint connector for the wire coming from the coil
was bent up a bit and not making contact with the circuit board foil.  I
tweeked(that is the official VW mechanics term isn't it?) it and now my Tach
works great.
Frustration is now all joy...how fickle we Vanagon owners are.
Coop