Bianchi Ranger HuSH, Blackhawk....
I'd check these firms & sources; Lawman Leather Goods,
www.LawmanLeatherGoods.com Bianchi;
www.Bianchi-intl.com Blackhawk;
www.Blackhawk.com .
Lawman LeatherGoods markets the popular STU treated leather rig. It's custom and may take several months to get. EDIT; Lawman Leather Goods also has a new line called the Big Hawk. It's a lot like the STU but made for custom scoped revolvers with any length barrels,
. See the main site for prices & ordering details. I suggest contacting the office directly before you order to insure sales/customer service. This holster may not be in stock or take a few weeks to obtain due to custom service.
El Paso Saddlery sells a few holsters & outdoor rigs for revolvers with scopes.
They are in El Paso Texas.
ClydeFrog