The National Park Service publishes preservation briefs to provide guidance on preserving, rehabilitating, and restoring historic buildings. To access the preservation briefs, please follow this link: https://www.nps.gov/tps/how-to-preserve/briefs.htm
The State Historic Preservation Office offers a multitude of resources for property owners of historic properties including statewide surveys, nominations of eligible properties to the National Register of Historic Places, environmental review of state and federal actions affecting historic and archaeological properties, technical assistance to owners in the restoration of historic properties, grant assistance for historic preservation projects, technical assistance to local preservation commissions, and historic preservation education. https://www.ncdcr.gov/state-historic-preservation-office
The State Historic Preservation Office also provides assistance with coordinating historic preservation tax credits for rehabilitations of historic buildings: https://www.ncdcr.gov/about/history/division-historical-resources/state-historic-preservation-office/restoration-6
The Window Preservation Alliance was formed in response to requests to have window restorers exhibit at regional and national building and historic preservation events. Their goal is to connect property owners who wish to save their windows with professional who can provide the assistance needed. Their page has a directory page with company's who can provide assistance with preserving historic windows. Please note that these are not recommendations but simply guidance to help you get started: https://windowpreservationalliance.org/
Preservation North Carolina promotes and protects the buildings and landscapes of our state's diverse heritage. Preservation NC acquires endangered historic properties and then find purchasers willing and able to rehabilitate them. https://www.presnc.org/property-listing/
The National Trust for Historic Preservation goal is to save places where our history has happened. They are a privately funded nonprofit organization that works to save buildings and revitalize downtowns. https://savingplaces.org/
Gaston County Historic Preservation Commission safeguards the heritage of Gaston County and its municipalities by preserving any historic sites therein that embody important elements of their cultural, social, economic, political, or architectural history.