FWIW, AFAIK & IIRC (I just love abbrev.) the metal-cased Horizon did not
appear until several years after NorthStar made its appearance with its
original model. The wooden case was veneered plywood stained walnut in
color. I don't believe that it was walnut veneer.
The end pieces of the Sol were solid walnut. The story goes that a friend
of one of partners in ProcTech had a wood working business with lots of
scrap walnut available, so the Sol had its 2 side panels supplied in that
wood. The kit version had instructions for finishing the wood with tung
oil.
I still have several Sols (my first computer) and several Horizons (all with
wooden cases). I think Allison has (had?) at least one Horizon with the
metal case. Once I get a round TUIT, I plan on making a walnut case for my
reproduction Mark-8 (the round TUIT being the most critical component and
one I have not yet found).
Bob Stek
Saver of Lost Sols
(should be a bit more active now that I have officially retired)