Might be able to do it if it is an exact duplicate and you have the
FAA-approved paper trail to prove it - not likely. Even though it may
look exactly the same, there are probably substantial differences you
can't see.

Want to make your own part see -
http://www.faa.gov/avr/afs/news/arch...2002/Parts.htm

If I were you I'd find a PMA replacement. That would be the legal and
cheapest option. Your mechanic can install a different PMA part as an
alteration with a 337 if you can't find the right one.

Just because you may find some A&P that will install something doesn't
make it anything other than an illegal bogus part that leaves you both
liable. I suggest that if you want to do this type of stuff, sell the
certified aircraft and try homebuilding.