20 Years ago i built a pinball game for part of an A-level art & Design project. I dug it out of storage recently and took it along to the UK pinball Party (http://ukpinballparty.co.uk).
The game was based on the Bally Hit Future Spa from 1979 and was all original playfield, cabinet and back glass creations while keeping the original rules and board set.
Was a fun weekend getting it back together and playing it again after such a long time. It was also nice to get such great comments from fellow pinheads. 20 years really went by fast!
See here http://mypinballs.co.uk/highvoltage for some more pics of it when first built.