Check the shock mounting bolts. If the metal spring rolls in the shock eyes are larger than the bolts (by too much) the play/slop will cause
a clunk in the front shocks.
Hoping the other guys will respond. I replaced my tank (85) some 12 years ago and I don't remember what I used. I think it was some old rubber belt from work.
Go to one of your local automotive stores that sells paint. They should have the books with chip colors. Look through the samples and pick what you want.
I agree that the truck in the photo is most likely not a factory color.