It's a strait-drop holster for a large-frame SA revolver with a 4-5/8" or 4-3/4" barrel.
The brass buckle is part of the holster.....so, there aint no loops.
The OP says it's dark brown, the manufacturer call's it "walnut oil".
Don't know if the one for sale is RH or LH.
Here is a picture:
http://www.cowboyneeds.com/114.html