That said, it is clear that maintaining a CofA aircraft is becoming uneconomic. My a/c is one model adrift from a permit so components are costing between 50% and upwards more for the Form 1 paperwork than an almost identical aircraft. Some components are not available at all.
You don't need a Form 1 for parts for a CofA private plane. Any documentation showing batch traceability is OK. The FAA 8130-3 is a popular option.