It looks like two issues:
1. Table mistakes in the Obelisk table entry - one extra turret was in the tables, and no subsystems were present in the table.
2. At some point in the distant past the high poly Typhon model had extra turrets. One of the restorers must have saved some of these missions with that model active. The current model doesn't have those extra turrets, but they were saved in the mission files. I have resaved all of the missions with the current MediaVPs active, which will clear that issue.
Version 2.6.1, uploaded to knossos fixes these issues.