I had to get more brass nuts to make more of these things. I knew that the flat nuts I had would not work for a 5mm adjuster; either the existing hole was too big or the nut outside was too small. Then I saw my local hardware store had 8-32 brass wingnuts:
The nut costs more but that's not a big factor, it's just as easy to make. I got some 10-24 wingnuts and will make a few 6mm versions like this.