I had intended to use a UP-Strap but didn't like it so i used a old Lowepro strap and converted it into a R-Strap with a RRS clamp on the end.
I started with a piece of 1/8 SS wire (A) and bent into a D shap (B) then welded it to a SS bolt (C) end result (D) which is then screwed into the RRS clamp, took the strap to an upholster and had it sewed together and added a pocket to hold a card and a battery.
Then i wanted a dual strap so i converted a Op-Tech dual strap into a R-Strap I took the 2 front straps off then i added the slider to the back strap but then i found the cameras were hanging to high so i went to a pet shop and got 2 dog leashes and replaced the original straps with the dog leashes with an adjuster on the back side of the strap so i can adjust the length so the cameras hang at the right height.
The original strap
This what i did to it
Attached to the strap
With the RRS clamp attached
Attched to camera.