Close to stock I could get Z button and D pad on a classic GCN controller, you will need the right-angled metal-spring piece for the Z button. One of the stock Z models also requires a 1.6-2mm thick wire roughly 11-12 mm long to be inserted to make the pivot point which will last longer, labeled "recommended". The other stock is a two piece, but won't be as strong as a steel wire version. For the wider Dpad it is a two piece slot fit.

Added a PS3 and PS4-style D-pad, they are thinner in parts, and feel bit more ergonomic than the flat Dpad I originally came up with.

2021: GCN TALL Z.ipt and .stl are for the mega-sized Z button.