I'm in Maui, sitting back between dive days, killing time, what a better place to spend time (wetpixel).
I know this is an old post, but looking at the D ring, I would have to wonder how it was manufactured. If I needed the same one, I'd probably make it in two pieces of stainless steel and then weld the two pieces together, I can't imagine putting the pieces together then doing the final bends into the tube.
BTW, had a chance to attend one of your seminars a few years ago, you have improved my lighting and reduced backscatter.
I've been a diver since the 60's and have machine shop skills, have built housings, etc. I just modified an Ikelite housing made for a Canon 7D into one that would accept a 7D mII, Ikelite said it wouldn't work, never give up.