I think the OP intended to end this thread. I hope I'm not offending anyone by keeping it going for a little bit. I've begun my parallelogram mount using cherry. I've increased the dimensions a bit and added bronze sleeve bushings in the main pivots. I've also increased the size of the bolt that attaches to the mount to 3/8 inch. I'm using oak for the vertical pieces. My largest bino now is a 10x50 Orion that I bought years ago. The optics aren't terrific. I intend to get a set of 80mm or maybe 100mm binos eventually.
What is the black metal fitting used for the rotation point in your photo?