I am sure there is somebody somewhere that would love to have your 76 as a project. The fact the parts are all there is a plus. I have no idea what the real world value of it would be, but here in the deep south I would think that a starting price around $3500 wouldn't be unreasonable.But be willing to take offers) I have paid less than that for complete trailers that were one step away from the scrap yard and slightly more than that for trailers that needed work. Pictures would be a big plus. Also FWIW the Ambassador is a 29' trailer and is not as desirable as say a Bambi or Tradewind which are shorter and lighter.
Good Luck with you sales and when you do sell it make sure you point the new owner towards this forum...from the sound of it they might need it