@Wayne Brooks I'm not exactly sure of the actual process but when I had looked at getting into doing overages locally, I went to the tax assessment office in person and the supervisor there explained to me that they don't have a tax overage list because they don't hold onto the money, assuming there is any overage. She said they usually notify the previous owner there is a balance after the taxes are paid and a check is usually cut. She also told me they get lots of people coming in to ask about it after some local guru program has been through the area. If it's unclaimed, then I'm sure it's remanded to the state to hold as unclaimed property but Alaska does have a statute that caps the percentage of finders fee to be charged when handling transactions of that nature.
If you learn of something different, please share, but that is the knowledge I turned up from the fruits of my research. I am not all knowing but have found that Alaska does have some unusual methods for doing things compared to other states.