Excellent!
The video of the Micropin on IPDB and YouTube is mine. I also posted schematics to IPDB for the version in the video. There's a later version (with Micropin inscribed into the front of the cabinet) that uses a different schematic. This cabinet can be seen in the photos on IPDB.
The ball is not a standard size ball but I'll have to take mine apart again to measure it. To my eye, it's about 3/4" the diameter of a standard pinball.
I'm only aware of three other of these in existence. Yours is now the fourth. I'd love to hear how you found it.
If you have any questions, you can pm me at randy _at_ colordmd.com.