Yes, it is different because I'm guessing those parts were previously built by someone for "education and recreation," which means they count as 'amateur built' on the Form 8000-38, fabrication/assembly checklist. They do not have to be built by you because any number of people can contribute to building a homebuilt, as long as they are doing it for education/recreation. The parts should not count as being fabricated by a commercial entity - because they weren't.
So the answer is YES, you should be able to rebuild the plane, easily comply with the major portion rule, certify the aircraft like it's a new homebuilt and obtain a repairman certificate, as I'm guessing that's your motivation.