BIG + 1 for Blade Tech. If it's not a stock item, they will make it for you. They made an OWB strongside holster for my 3" 629 .44 Mag. They included the "drop offset" piece that drops the butt down and angles it away from the love handles. This was not a 4" N frame holster they chopped to 3" The "Trail Boss" has a memorable silhouette and the kydex fits like a glove.
For the blasphemers, I had him make a holster for my modified Glock 21 with a next-gen combat light from SureFire attached under the frame, with out a rail. He asked for a week to think about it and I got the holster the next week. The weird curves of the light don't snag on anything. Same draw stroke, presentation, fire, and recovery. I had to remind my self to press check from over the gun but the light is too big to reach around and SAFELY press check.
BTW IIRC the only difference between the 581 and a 686 was the steel, 581 blued,686 stainless. 681 fixed sights 586 adjustable.
Train hard brother!