Let's set something straight. You said, "Corrosion is a major problem with aged aircraft." - It is not. - unless the operator is NOT following the required "aging aircraft inspection" requirements, which are designed to detect potential problems before they become airworthiness issues, and correct those deficiencies. Baltia's first aircraft is regulation compliant.
You said, "Once it’s there, it eats through the metal like a cancer." Not true, unless it is left untreated (and moisture is present long-term) - and the "aging aircraft inspection" requirements identify potential problems and the resultant treatment/repair then prevents it from spreading. Period. These are preventive inspections/actions.
FYI - the "sister ship" is what has commonly been referred to on this board and elsewhere, as the other Delta/NWA aircraft that Kalitta is holding for Baltia. Nobody else has confused that term with the aircraft that we all know was set aside in Malaysia.
Incorrect information? - You wrongfully assumed that Baltia was starting with the Pakistani aircraft.
Negativity? - It's when someone states a partial truth about a topic (corrosion concerns), applies it to the subject at hand (Baltia's aircraft), then extrapolates to an untruth ("once it's there, it eats through the metal like a cancer", creating by association an unnecessary fear/concern.
Let's not quibble words anymore - let's do some due diligence and share valid information.
Good luck to you.