This is really exciting, and from a technical standpoint, there is not better qualified person to succeed in such and undertaking than yourself.

The most important part of your idea is the "father / son bonding". I can speak from experience that this will be the BEST aspect of the project. Your son might not know it now, but he will be grateful for everything he learns from you (I know my father did the same), and I spend as much time with my son teaching him about pinball. For a 9 year old, he knows a lot about games - as in the names etc.. No matter what the outcome, the journey will be the most rewarding.

I'm keen to follow the progress, and who knows, the first "Homepin" might be my first NIB for many years.

Good on you Mike, the interest in pinball is increasing and it might be time to ride the wave !