Mike, your idea has crossed my mind several times (fantasised) over the past couple of years. You and your son have proven that you can take the first steps to reality by your Chinese ventures. I congratulate you both on your drive and enthusiasm.
I would certainly buy your flat pack with several criteria in mind.
Keep it simple.
Stick to proven themes and playfield designs. Maybe some research with pinball enthusiasts for ideas.
Artwork and style execution need to be spot on.
Component quality is a must.
The price point has to be enticing.
If you go ahead, you would be one of the first with such a concept and with current economic climate, onto a winner.