Today I finally got the dash together again, after removing it to replace
the blower fan which has been seized for several years. Not a pleasant job,
but not too difficult, especially with the help of detailed instructions
posted from several listees over the years. The heater box had been opened
before, likely by the dealer, as the PO had nearly all work done there. The
blower looked original, so I assume the reason for previous repair was the
heater core, which looks fine still. The box was held together with small
self tapping screws on each tab, which worked well. Most of the foam was
still in decent shape except for the surfaces of the "flappers", which had
turned to dust. Both of the box mounting screws (M6 x philips head) on the
inside were seized and snapped on removal, so I had to drill them out and
re-tap the holes. Most of the time was spent removing the washer nozzles and
cleaning rust behind, applying POR-15 and re-installing. Other than that, no
major issues. Oh, I also applied some ashpalt membrane stuff to the inside
of the sheet metal for sound deadening.

Any reason not to replace those wierd headless bolts holding the steer
column to the dash supports with standard hex bolts?

Lots of dust from many miles of dirt roads, which leads me to wonder if I
can come up with some kind of cabin air filter in the airbox opening behind
the grille - has anyone tried this? Obviously some kind of material that
would tolerate moisture would be needed.

We leave in a few days for an Easter trip to the interior, so it will nice
to have a working fan again. :-)