JMHO: Choose your roof coating , and follow all the pre application instructions to do with cleaning before application . Then apply .
Unfortunately, given the current condition of the roof ; from seeing the photos ; don't be surprised if the coating doesn't stick .
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.