Hello - I have what appears to be a galvanized steel roof. House was built in 1970 and I know the lower roof in the first photo is possibly newer as that is over a garage built in I believe the early 90s.

I was wondering what I should do about the rust damage on the roof and some of the flashing. I haven't noticed any leaks internally which is a relief but I was looking to access the brains trust here to help me understand when I should do something preventative like rust converter > Primer > Paint vs. determining when it is time to replace the roof.

I have 2 solar arrays installed and as you can see it is a flat roof with about 100mm space between the ceiling inside and the roof. Thanks in advance for any advice.