I love Casey's bluing paste. I've gotten some excellent finishes using that stuff, of course the polishing is the key. Corrosion resistance of chemical bluing is actually much better than reported on gun forums by "purists" who only trust hot bluing/salts process.
If I had to dissect and clone that parts group in your photo.....then get all of the bugs worked out of the reproduction part during the operational testing phase...iy could take a month if everything went well on the first try...!
I've got a similar mechanism to try to reproduce on my own ....an early Jeep Cherokee door latch assy that is no longer easy to find.
Well, you're way ahead of me. At least you can give it a go. Really, the most difficult thing about the stamped parts is bending them correctly. Rog and I have discussed metal bending. I got one of those small metal benders just to play around with it and see what it is capable of doing. So far, I'm not particularly impressed. It's not precise enough. And, I can't find a bender that is designed to make precision bends. I just don't think one exists.