Coupler for Gopro Hero 3 to Brunton Echo monocular = airsoft scope-cam

I am trying to devise and build a "scope-cam" for airsoft use... a camera that mounts to the airsoft gun and mimics the view through a scope. Since I had a Gopro Hero 3 handy, I thought I'd try to couple it with a Brunton Echo 7x pocket monocular that I also had on hand. This is a simple coupler to connect the two together, though it requires unscrewing the eyepiece lens from the Brunton Echo first.
I apologize for not having more pictures of the result, but I managed to break my Brunton ech