I think it looks great and would be a perfect replacement supplied as a factory assembled unit. I really don't think the average pinball hobbyist is ready for surface mount.

Fair - I'm a hobbyist and do surface mount as a rule now. Just easier to assemble IMHO.
I may redo the design one day in thru hole - but as you indicated; there are other replacement boards out there.

My replacement board fits into the exact screw holes of the original - uses easily available through hole parts that can be bought anywhere but adds a microprocessor so that bumper timing is adjustable and allowing a power up delay. It comes either built and tested or as a DIY kit.

It also includes a test switch (to fire the PB) so that fine tuning of the mechanism can be made while the PF is lifted.

Good ideas - but for the moment i went for low cost. I had no idea your design existed; but it goes to show that their are more than one way to solve the existing problem. Microcontroller is a bit of an overkill; IMHO - but certainly makes for a flexible design.