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)