The back of the sheath is quite worn and I don't see any stamps anywhere. I will post some more pics tomorrow of the gun belt and the back, sides of the scabbard.
My guess is the holster rig was brought to Johnson and the sheath combo was riveted on there, or, the sheath combo was brought to the holster maker and was riveted on there.
I don't think any of this rig was made by Johnson. Look closely at the stitching. Especially at the throat of each sheath. It's not back stitched. At least not the way Mr. Johnson did it.