Nice truck! Your paint looks very similar to mine. If you start on page 9 of my build thread
here you will see the process I used to paint my bed to match the original patina on the cab. I got the paint from Sherwin Williams. My dad had a connection through work and they have a nice single stage paint that gives you a similar look to the original single stage paint. The short of it is paint it like the factory did (black primer/sealer, single stage color), and then age the paint to match the original patina. How aggressive you go depends on how faded your truck was. Mine wasn't really that bad so I used 400 grit to slowly work the paint in common wear areas until the primer just started showing through. Then I worked up to 2000 grit to level everything. From there, what you do is up to you. I like the dull look so I left it and just finished it off with 000 steel wool. Of course, you could go all out and polish it up to shine.