I am redoing the undercoating in my 69 Roadrunner. I bought a gallon of Rick's stuff, but now I cannot use what I had to spray it. I am left with the fuel lines at the tank and part of the gas tank and it would be nice to use some spray bomb to finish my work. Is there a product I can buy at a part store that would be good enough? Nobody will probably notice if it's not perfect, and it was not perfect in the first place anyway. Thank you, guys.

I used the same stuff from Rick for some touch up. I used several different types of sponges to dab the undercoating on. Practice on a piece of cardboard until you get the right texture. You can't tell the old from the new on mine now