Good call on the buttons post.
I've been trying to collect Nintendo buttons and sticks for a good year now. Mike's Arcade had tried to run a Kickstarter to produce proper 1to1 replicas, but it was underfunded by a couple thousand. My experience is basically that the DK Orange and Gen 1 DK Blue buttons are the hardest and most expensive to get ahold of. Nintendo Vs buttons are the easiest by far. They have a slightly smaller hole size then standard buttons and when used with the proper microswitches and button holders they have a distinctive feel to them. Same with the Joysticks.
I didn't think i'd ever think this would really matter, but if you're building a replica Nintendo cab, its best you track down some original Nintendo controls. A good tip would be to find a populated Nintendo Vs panel on eBay or one of the forums. they can be had for $50-100 depending on condition and seller. in most cases that will get you sticks, buttons, holders, the works. Then you can rewire it, or adapt the Nintendo harness if you get one it. Vs. CP's make for good 2 player panels.
I'm also going to post this guide to Nintendo Buttons. I found it on KLOV.