I have someone coming to give me a quote tomorrow either on a new roof or can rust spots be fixed and is it worth it to stay with the old dimondeck roof and just repair and paint. The roof has rusted mostly at the edges on the seaward side but the majority of the roof looks sound with paint peeling because of a bad job last time. 

Being close to the sea and wild elements means I want the highest specs. The original roof was the highest gauge available at the time.

I would welcome some suggestions and advice as to what I should be asking for and any pitfalls. Does it make sense to only reroof the seaward pitch with corrugated iron, which wouldn’t match what’s there now. That side is not visible unless you’re on a ship. The other pitches look solid and it seems a waste of money and materials to tear them off. Thanks.