Here is a copy of the FAA paperwork and structural analysis and photos of the Shoulder Belt modification performed on my Ercoupe. It is also applicable to Ercoupe derivatives, such as Alon models. This modification has virtually no exterior indications of a modification except some additional rivets between existing rivets at one or two frame locations.[http://www.ercoupe.info/uploads/Main/ShoulderHarnessMod.pdf| ShoulderHarnessMod.pdf]]