Here is what the mount looks like:

I’m sure there are easier ways to do it, but I just used the top portion of this: (so just one 1/2″ galvinized steel pipe, 2 end caps and the GoPro tripod mounting piece.) I put the pipe through the top loop that is used to secure an umbrella on most bags, and then used nylon rope tied around the bottom cap down to the bottom umbrella loop to hold it steady.

If anyone is interested I’ll try to post a few more photos.