Very excited to see this guy! Not sure if it's a loggerhead or not, but I've heard they're the most common in the area, and figured a more specific ID would be more likely to be seen by an expert.
Known breeding location, approximately 13 adults uncovered in dry pool bed. Likely just arrived, no eggs and following heavy rains.
I doubt this was captive at any point. The skeleton is currently displayed in a small museum.
For my own reference, the translation of Chinn Hung's comment below is, "Loggerhead sea turtles usually have 5 pairs of side scutes. Olive turtles have 6 or more pairs of lateral scutes." (scutes are plates of the shell)
Museum staff were contacted. Museum is under renovation, and in light of the identification and lack of history, I was told the turtle will likely not go back on display when the museum reopens.