My $$$....
If you have the time & $$$, Id suggest a custom shop holster in a horsehide or "exotic" like bison, rhino, shark, elk, etc.
I'm not much for leather tooling but I have seen some excellent holsters & gear.
For top US holster shops/firms that can produce a Ruger GP 3" holster, Id see; Galco, Milt Sparks, Mitch Rosen, DeSantis, Don Hume, Kramer, Kirkpatrick Leather, Wright Leather Works, Ken Null, El Paso Saddlery, Mernickle, Tex Shoemaker, Bianchi, Del Fatti.
I like the Wright Leather Works Predator & the new "Master" series. Milt Sparks is widely known for 3/4" revolver holsters.
I'd contact the shop before you pay anything or order so you are fully aware of what they offer & how long the shop time is. Many custom holster places are way behind due to the huge demand for concealment/field holsters.
Clyde