I'll be watching this thread, I will be doing my weather stripping soon. I like the package Dearbourne has, lot of parts and priced reasonably.
I didn't use rust doctor, I found a different product called rust x. It was only $39.00 per gallon. After cleaning and scraping as much as possible, I coated with a simple spray bottle (it destroys spray bottles) the entire underside, trunk, & engine hole. Then swabbed the inside of the pipes best I could. Wear a mask!, and if you get it on you, you'll sport it for a few days if it dries. The stuff did amazing things to old rusted parts. But only time will tell if its any good.