Identical design maybe. Identical quality, not a chance. Certified aviation parts have to be fully documented down to the nuts and bolts as well as the metal suppliers and the quality of metal. In addition, these parts carry great liability that they don't see in automotive use. This means that the quality control on PMAed parts is a magnitude better. In the automotive world, a certain amount of failure in field is acceptable and carries little liability other than warranty expense. Make 'em fast and close enough, then let the consumer do the QC.
Bull crap. Why would Cessna make "a batch"? How many of these old planes are out there flying? How many are likely to need this part in the next year? The next five years? How much is a "batch" to you?
I guaranty that if you contract to make 100 of these parts from a drawing with a machine shop in this country, there is no way it's going to be $5 a part. Add in the paperwork, reporting and federal inspection required, and the price goes up. Toss in personal liability to the machine shop and the price goes up further.
How does this "shoot down" the accountants are happy thing"??
The parts prices are high, there is no burden of inventory and planes get scrapped. From Textron's perspective, what's not to love? Why would they release the engineering specs on them? That just means more planes will keep flying with owner produced parts and that's contrary to what they want to happen with these old birds.