I just redid a '56 Johnson that my son gave me for my birthday. Rustoleum matched both colors at about 90%. Only a true aficionado would know the difference. You may need to google the color on EBay, since Wallyworld may not carry that particular code number.
That said, Rustoleum is real good paint, but the stuff that you can get at North York Marine in Ontario is simply the best. if you run the boat in the water for awhile you'll see the difference.
But you get what you pay for. $5 a can vs. $20. Then again, 3 or 4 cans really is not significant.