Do Mustangs have an "NCRS" type organization?

[Wendell Allen]

For those of you not familiar with it, that's the "National Corvette Restorers Society". And I can tell you from experience that those in that organization have a level of understanding of the older cars that is unmatched anywhere else. They can talk about the most minute details and answer questions that help the rest of the world bring their cars back to factory likeness.

I'm wondering whether or not something like that exist for Mustangs. I'd like to join if so.

Thanks!
Wendell