Ran when parked a few years ago. Was it stored outside in the weather and rain or inside dry and clean? When you wind it up and pull the brake(or push the little lever), does it unwind, or are you saying that absolutely nothing happens?
You need to go to the wiki page and read Fred's guide. It will go through how to check your spark, fuel flow, and other diagnosis information.
Take pictures. If the crank does not move at all, you might have other issues.
I just restored a 77 nc50 shoot me a message if you need help.