Spoke to a government official about Alvin's plight and he said "why don't you fly the dermatologist to Bougainville?"
Spoke to Director of Medical Services at Buka General Hospital. Turns out the dermatologist working in Port Moresby's public hospital (at least I think that's where he works; they have several private hospitals over there) is married to a Bougainvillean, and he is keen to come over. Furthermore, he wants us to organise a week's worth of appointments for him so that Bougainvilleans get a decent chance to see him while he is in Buka.
Seems like good value for money to me. Am still looking into things so will let you know how it goes.