I'm know I am late to the party.
Been lurking a quite a while, but thought I would chime in for future reference when peeps read this. First post here on APUG.
I too had an (uncoated) 159 9.5 many years ago. I later sent it out and had it coated - a lab somewhere in the N.E. whose name I cannot recall. It was already a reasonably good lens, but the coating made a notable improvement in contrast / color saturation. Pre-coating, it was still nice - or I would not have spent the coin to have it coated to see if I could make a good lens better.
While it was no Nikkor SW or Super Angulon, it was a darn fine performer, and at 16 and down seemed very fine to my eye. Mostly used it with Ektachrome 50 64 and 100. I was a commercial photographer back in the late 70's through the mid 90's - and this was my go to for wide on 8X10 and also provided decent coverage on 5x7 when I shot that. If you need a wide, and cant find a 165 S.A or angulon, this one will certainly do a decent job.
I used a 90 a few times and it was certainly decent enough, but the angulons and SA's were much more common and since I used 4X5 far more often for very critical work (architecture and interiors) I had a Super Angulon which has much better in coverage. I have used so many lenses over the years 25+ years ago. I bought, sold, borrowed and traded more than I can remember, and have good memories of a few, bad experiences with a few, and a lot of lenses that were for the most part good, mostly decent performers. A few were spectacular, and there is a lot of good glass out there.
Occasionally you get a lens that just sings for you. If you do, keep it, or you will regret it. It matters not what the reputation is, what name is on it, or what kind of condition it is in. Just shoot with it and never let it go, except to the shop for CLA.
My favorite thing about these old gals is they are so SMALL compared to the Huge modern designs. If you are using a field camera a 90 - 120 angulon, and a 203 ektar makes for a super compact setup that will give almost everything you need for 4x5. While you may get one thats a dog, don't judge an old lens based on lack of a prestige name.