I'd ask to get a quote on replacing it with an aluminum roof with marine rated paint and see if you get a response.
After you fall off your chair from the quote then you have a chance to try something and know what your worst-case scenario is. I found conflicting information online as to if you can do a silicone coating on that type of roof... but you now know what you stand to loose. Brush off corrosion, install a galvanizing corrosion inhibitor, and roll down some silicone roofing coating, ideally under the panels and everywhere down-slope from them to the gutters. If it is too much of a pain to do under the panels, just go about 6" under the bottom edge and hope for the best.
...or try a Roofing subredit?