Nice job! When I first looked at the pics, one stood out instantly
http://gallery.me.com/benhdvideoguy/...C_3354/web.jpg
I said, they didn't have it in the hole! But then I saw the whole flat plate was movable.
When I installed my Novan collectors on the roof, I soldered on 3/4" screw on couplings.
looked like these..
http://image.made-in-china.com/2f0j0...n-Fittings.jpg
They connected the collectors to each other and to the up-down pipes.
And they made for a good leak-free install. It made taking them down easier too.
The hard part was using low-lead solder!