I suspect you're not going to find a Kydex holster maker who stocks a rig for your twenty-years-off-the-market/never-particularly-popular gun.
I have found this to be true. A Bianchi Model 100 (Professional) is a much easier item to obtain.
But here's the interesting part - probably common knowledge but I only noticed it when I bought two of these holsters, one for a CS-9 and one for a CZ 75 Compact. when you get on the Bianchi/Safariland website you have to fill in some blanks. Suppose you do this:
Maker: Smith & Wesson
Model: CS-9
Barrel length: 3"
Caliber: 9mm
Basically, that's the series of questions that everyone is familiar with, right? Other holster makers do the same thing so that's not a surprise.
Well, apparently, there are so many pistols of similar size and shape that the holster you will get has a short list on the base identifying the 4 or 5 pistol models that your particular holster fits. Even more specific, the Model 100 holster for the CS-9, which fits perfectly, has a one-inch, hard to miss sticker on the front that says "GLOCK 26/27".
My first reaction was that I got the wrong holster but, as noted above, when I put the CS-9 into the M100 it fit perfectly.
So, admittedly, Kydex is different than leather in many ways but you might contact one of the Kydex holster manufacturers and ask if their Glock 26 Kydex holster will work with a S&W CS-9. I'd wager no, the Kydex isn't as forgiving as leather, but it's worth asking.