The question of whether it's too late for the N20 class is only resolved by an agreement among the class members as to the vision going forward.

You should look at the Viper 640 class for inspiration... The boat was given up for dead but a new rig was part of a clear vision and buy in from the sailors resulted in a big rebound centered around a great regatta circuit and now they have a full page add in Sailing World listing their major regattas!

How not to manage the future??? See those dead boats that you just listed....