As I'm sure you know, it's worth what someone is willing to pay. And to that end, anything you can do to show it's construction, be it photos, a computer model, or a physical model all help. Also the more assurance that it will go together correctly helps. Show how it was dismantled and cataloged helps. Are you able to help re-erect it? Was there any damaged members or joints that need to be repaired or replaced? Was the frame straight? If not it has to be straightened in that area. It's common for water damage to rot something and cause a bow or movement in that area. It needs a qualified timberframer to repair or cut replacement pieces. Are you? All of this will go into how well you are able to sell it, provided you find someone who's need fits the size and design of this frame.