Very interesting story. Maybe if you're ever having another conversation with a FSDO, you could ask them a question that I'm too much of a scaredy-cat to call and ask myself. I fly an ultra-light, I'm thinking of transitioning it from an ultra-light to and e l s a or an experimental light sport aircraft. Reason being rather than pay someone to use their aircraft if I do it this way I can build and log all the hours in something I already currently own. I can't really find any information that directs me on the process but I saw that you spoke of after I guess a power plant change having to go through specific requirements for your airworthy certificate. I guess my question for them and short is that if I am flying an ultralight and want to just transition it to an Elsa outside of having to write a poh for and other documents if it is required to have flight testing, who would do that testing and how many hours would be required? Meaning I'm trying to figure out and in ultralight going to an aircraft with a non type certified engine Etc do I simply give them the documents and get a certificate or do they actually have some type of flight testing process that they would put the aircraft through. I also kind of thought maybe if I make a documentary on the process of doing that ultra light to light sport it would be a pretty cool concept because I can't find anything else that would cover that. Best wishes and when you get a chance tell us more about what your aircraft is the history behind it and did you ever do the generic records request from the FAA and get all the history documents?