The time of these aged piston twins is over. Fuel prices alone (AVGAS) will be a show stopper despite all the other fees and duties to setup/run an Air Transport Operation. Just look at Mainland Air and their short-lived OR-CH service. It simply was not commercially viable. And also speaking as a passenger, who wants to cramp into an AZTEC and the likes, unpressurized exposed to all weather?!?
I think a small operator could snap up some niche market, perhaps WN-AP or WN-WS, and use a modern aircraft such as a PC-12 to serve it successfully.