For guys curious about amateur builds and the misconception that the FAA doesn't allow parts from certificated airplanes? Here's the 51% builder score sheet. For guys like me that purchased approved 51% kits the manufacturer's portion is filled in and where they took 1 point you're not eligible for credit on the line. Some lines will have 1/2 point assigned to the manufacturer with a half point available to the builder. It doesn't matter who the manufactured part came from. You'll also see a column for commercial assistance. There's no problem with that, either, as long as the final math works for the builder. The rule requires the amateur builder to have 51% using this sheet and the adjustment formula provided at the bottom of the form. As stated in other threads, the approved 51% kits make life a little easier because the manufacturer's contribution is pre-determined. If you collect a pile of parts and want to assign or share manufactured part points? You should run it by a DAR before you get too far to make sure they're in agreement that you can achieve 51% with your builder plan. Why do I care? Because I'm enjoying the E-AB category and believe 95% of private operators of certificated airplanes would have the same opinion if they gave the E-AB category a go.