One of our retired Sgts has been making holsters for a lot of years. He made the one picture below several years ago. It's been carried a lot and still looks like new and has retained it's shape and condition. He does a lot of leatherwork, not just holsters. The guy is a perfectionist. He uses very heavy leather. Note in the picture how even his stitching and finishing is. Cost for a pancake like the one pictured has been about $40 and he has about a 1 week turn around.
If you're interested in talking to him then drop me a PM/email and I can put you in touch with him.
The Glock holster below is in mahogany basketweave.
The one below that is in brown basketweave for a 4" Model 63 (J frame). I asked him to intentionally make that one ride a bit higher with exposed trigger. It hasn't been carried as much as the Glock but when it's been carried it's been in a tougher environment. I carry the 63 hunting so it gets beat thru brush, climbing fences, etc. You note a mark on the right side by the belt loop. I got that climbing a fence. It didn't cut the leather, just made an impression.
I don't know if he has a mold for a 3" J frame but if he doesn't I can loan him one to use for your holster.