I kind of knew the answer but was hoping for some gift of grace from the State. Everything said makes sense.
The first plane I built 20 years ago MI required all the receipts. Kit, Engine, Avionics, Paint, et.....
The last 2 planes they changed the requirement, they didn't want any receipts. They wanted the value of the plane. There are enough RV10's out there now that they can bounce the number you tell them up against others for sale. If you were building something somewhat unique it's hard for them to check the value. Not so much with any RV.
Gary
RV10
N100JV
Find a tax friendly state, Delaware, New Mexico, Wyomimg. Delaware and Wyoming LLC's work great.