Thanks Graham, in the past few weeks I've continued work on the mount, and now I'm almost finished it. The A-Frames don't have too much wobble, which is good, I think it definitely helps that I tapped the top so it the pivoting bolt also holds it together. The altitude friction isn't heaps though, so I'll try wingnuts and springs and I also bought two of these:
https://www.amazon.com.au/Clamp-Ligh...s%2C293&sr=8-9. But if you've got any good ideas on slowing down the altitude movement I'm all ears. I already tried washers with various materials so I'll see how we go with springs.