brownfox, I’m still cutting on my original LS 2x2, I just haven’t had tome to put the Pro together. The plasma unit is a Everlast 80 with a 1.0mm tip cutting 12 gauge steel at around 95 ipm and 50 amps. I use 1/16" thick angle and 1/2" dimension for the channel the the mirror slides into. I have a small jig I use to put a gap between the edge of the mirror frame and the angle this way it’s the right size to take the weld bead (and no I am not a welder I am a grinder LOL) . I can send you some pictures of the jig that I use to make sure the gap is exactly the same on all 3 sides and it holds solid in place to put the tacks on.
I appreciate the questions, I am by no means not a creative person by nature and my wife teases me about finding my creativity at 60 years of age.