Nice work!
I made a finder too from a 7X50 pair of binos. I chopped the bugger in half, keeping the focusing barrel on the 'scope' I was going to use as the finder.
I installed a set of cross-hairs to the EP which is easy to do, and you may like to do as well.
I removed the eyepiece and found its focal point by looking into the EP and poking wire into the other end of the EP. I then wove strands of copper wire to make the cross hairs. The strands I got out of a length of an unused telephone lead as these are the finest strands that are easily got.
The wires are kept from moving with a tiny amount of epoxy glue.
I kept the "monocular" set up as I prefer straight through finders, but this rig gives me correct image too,
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I've since change the wooden block for alignment for a simple camera ball head attachment.