Organized Chaos is 25-1/8″. How sure are we of the precision of the position of the bulkhead relative to the transom? If it isn’t an intended measuring point, it wouldn’t be surprising to find that it varies by as much as 1-2 inches. Manufacturing techniques were good, but not quite up to modern CAD/CAM standards. Would the lifting bolt on the keel be a better reference?
Either way, I’m going to have a hard look at the rake on the boat. Has anyone measured the distance from the top of their mast to the bottom of the transom (no backstay tension)? Having both the position of the mast step and the aft measurement would allow for the most consistent results.