Not using it for the outside, just like door jambs, and around body parts before I put them back on, under the trunk, ect... I'm having to do this a little at a time, and I need to also cover body work/rust work untill I can get it painted. Then where there were repairs made, sand back to the metal and prime with the proper stuff. Make sense?
I was thinking about asking the Sherwin Williams if they have the color I am intrested in and if they do I am sure they can can it. They already told me I would have to buy a case as far as cans. I had asked in the past about a different paint. I only needed 1 can so they showed me the bottle and pressure can and that works great for smaller mix your own stuff. A case for my car I think is worth asking about.
I was thinking of doing a similar thing too. I wanted to paint the door jambs and other areas that don't show. Then let a professional paint everything that actually shows. I don't want to pay the $100 per door jamb that they want. I figure the current grabber blue would be easy to find.
Sherwin Williams on 121 in Lewisville just told me it's $8-$12 a can no minimum quantity. They need a couple of hours lead time and having the code helps with the search. This is what I'm doing next spring.
You can also buy Ford paint colors on-line from this company. I used them to rattle can my engine compartment. As long as you can get the paint color number from your door jamb you can do a lookup on this site by year and make. Just be aware that this paint is base paint and will be a flat finish. You will have to clear over the top of it. http://www.automotivetouchup.com/
NAPA sells sealer primer in a rattle can that is real good. I have used it just like you are saying....when you are doing body work a little at a time. It seals out the water and moisture from the air until you can get around to real paint. You have to scuff it with a scotchbrite when you are ready for topcoat. Cleaver
They do have the older colors,looked up brt red for my 71.. 19.95 per can for base paint 12oz can.... could be a good way to do jams though...