FYI, the ST Clone NV Assy's are not made by Leonard, but for RSM. RSM obviously has them made in a 'yob shop' in the LA area. The first one I used was in a Magnum XL .25, and it had to be fully closed to be lean enough. I think it was because the threads weren't long enough. I took it out of the .25 and put it into a .46LA and it worked perfectly fine, due to increased fuel requirement of the bigger engine. The Clone thread is different (USNEF, I expect) than the metric thread of the genuine articles. Doesn't make them bad, but they don't interchange.
One thing you might appreciate knowing...it's that bent handle that makes the ST type NV tend to self-adjust. Put a round knob of some sort on it and it won't do that. A hex nut and matching nut driver would work, but soft solder isn't going to hold up, I don't think. Sta-Brite might work ok.
The very best NV Assy's you can get are sold by Randy Smith.

Steve