If you decide it's too much for you to attempt, Sargent seats will do the same thing for you, using your seat. They quoted me $150-$300 (sight unseen), depending on the extent of work that would be done to do what I wanted. (I found the Burton DS-001 shortly after, so never pursued it.)
ozbon, huge kudos to your friend for a bang-up job. That's an amazing looking seat.
“The strong survive, but the courageous Triumph.”
― Michael Scott, "The Warlock"