Looking for recommendations for an OWB holster for my new S&W 586-7 Comp 3” bbl .357 7rd revolver. I need it to fit well, no thumb break, leather or Kydex.

Thanks!

I carry mine in a Kramer Horsehide Belt Scabbard. Fits all the criteria you mention and with a good belt you don't even know its there. Not particularly cheap and takes a few months to get one, but worth the wait.