My experience with Moisture Cured Epoxy i.e POR/Chassi Saver was it's expensive and requires a uniform rusted surface to adhere to or it flakes off in sheets,and it allows moisture to migrate underneath if any cracks develop causing more rust than if the part was left in bare metal...
One Gal of POR is over $150 plus the activator.
Two gals of SPI epoxy primer including activator is is about $180 it has a 5 day pot life after mixing which can be extended another 5 day by mixing/adding more to the pot, has a sandable finish (unlike the MCU's) and can be found on several Pebble Beach concours cars. (again unlike any MCU's) and the black SPI epoxy has UV inhibitors in it as well.
