I live in a Coop on the Upper East Side/ Manhattan on one of the "Avenues" An All Cash Bldng, just learned my name is forged.

I live in an old guard bldng on the Upper East Side of Manhattan, an Avenue address. I have uncovered that the Head of the Coop Board has forged my name on the documents/proprietary lease, etc. for the Corporation, and there is no Raised seal or Witness on that important page. My signature appears elsewhere and all are forgeries. It's an All Cash building, and so the documents are not "in the bank", as the shares have no debt. What kind of a lawsuit can I or should I bring against him, and is the rest of the Board responsible for his actions as well? This is completely provable and I have reported it to the authorities.