Funny you say that. What rusted on mine was the drivers side fresh air vent opening. My fix, make a steel cap that went over cowl attached with self tapping phillips screws and clear silicone. Won't leak now! Color matched it to car and if wiper motor ever fails, I can remove cap and replace. Isn't going to get driven un rain or sit outside so I should be good.Nice work. One thing to check when those cars have rust like yours. Check the inside of the cowl where the vent opening is at the heater box. Many times that piece rusts away and you will get water in the car every time you wash the car or if it rains.