Here is my harness build. Hopefully the images work cause I'm using my phone...
So, after studying all forms of references I worked out that he has the two shoulder straps which attach to a horizontal strap, which in turn goes under the arms and attaches to the back holster thingy (and obviously the shoulder straps also insert into this holster thingy). It's pretty much a custom build because I could not find anything commercial that matched and I wasn't happy with how the weight-bearing harnesses sat/looked. The horizontal strap is actually two pieces of webbing that thread into a step lock; one side is fixed with an eyelet and the other attaches with a press stud, so it's easier to get on and off.
I bought some 32mm webbing, eyelets, nylon sliders, a press stud, and a couple of strap keepers (I actually couldn't get them in the right size in nylon so had to spray paint metal ones). Technically the front horizontal strap has a step lock but they didn't have any in the right size so I just used one of the sliders. It still works but the webbing doesn't sit as flush as it would with the step lock but oh well.
I bought a cheap backpack from the Reject Shop and unpicked the straps. I made a pattern for the back harness holster thingy (where he holsters the Skorpion) and cut out the back of the backpack (the part that would rest against your back. Including the foam padding and lining). Pinned the shoulder straps and webbing to the top corners, pinned the horizontal strap webbing to the bottom corners and stitched around the edge of the entire thing. I was on my own trying to measure it all out and check fit so I'd recommend getting someone to help to make the job easier/faster -_- Anyway, once you've worked out the correct length you need for everything it's a matter of adding the sliders, strap keepers, eyelets and press stud where they're meant to go. The eyelets attach the shoulder webbing to the horizontal strap. And I ended up applying a dab of contact adhesive to keep the webbing on the backpack straps. Now, I haven't added the weird bit in the centre of the back holster thingy where his Skorpion attaches to but overall it looks accurate and if you wanted you could probably figure out how to do that.
Sorry for the long post but hopefully it makes sense. Lemme know if the images don't work.
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