My first thoughts would be to send it back for a refund as that Camera could best be described as water damaged, and at worst, scrap, for parts only. The fact that it is working truly amazes me
That camera does not appear to have suffered normal minor water ingress or condensation damage. It looks more like it was submerged in sea water and plenty got inside the casing. Hence why I am amazed that it’s PCB tracks carrying power gave not dissolved away.
I have worked on a lot of merchant marine equipment that has come from salvage yards. It ranges from perfectly OK , just needing a clean, through to total corroded junk. The problem with water ingress, especially salt water, is that it causes corrosion of the PCB tracks if power is applied at the time of ingress. It does not take long to do a lot of damage. PCB vias and IC legs just corrode away ! Having repaired Ex sunk HF radio gear I know that the equipment continues to suffer water ingress related issues long after it is repaired. If it is a salt water drowning, you really need to strip the boards of all components, or the IC’s at the very least, clean them thoroughly in an Ultrasonic bath and then leave the PCB in a special salts extraction solution that draws the salts out of the PCB material. Failure to remove any salts that exist in and on the PCB can lead to future corrosion related failures. That is, of course, if future reliability is a concern. If the water damage is purely rain ingress, the stripping of the PCB is not needed and just a good clean in a swept frequency ultrasonic bath containing distilled water is often enough.
Any component that looks to have suffered corrosion needs to be removed, carefully cleaned, inspected, tested (where possible) and re-soldered to the PCB. Any part of the camera found to be damaged should be repaired or replaced.
Now to the optics and microbolomter....... neither appreciate submersion but your lens objective is showing evidence of such
The Lens coating is a bit of a mess to be honest. There is nothing that can be done by a hobbyist to repair that damage. You need to disassemble the optical section and inspect the elements fir damage. It is likely the other lens element(S) suffered corrosion related harm as well. The AR coating that is flaking away can flake off on the internal lens faces and get onto the microbolometer window or Interfere with the FFC flag mechanics. The Microbolometer may have suffered corrosion or staining of its window. It’s leads may also be corroded and any socket used for it needs to be carefully inspected for corrosion. Disassemble the FFC Flag assembly and its motor/solenoid and inspect for corrosion.
In short, this is a very involved restoration project that far outweighs the value of the camera in a commercial world. If it was cheap and you want the enjoyment of the repair, like I often do, it is worth the effort. Do consider carefully whether you want to dive down this particular rabbit hole though
Fraser