Great job on the paint and free is a great price!
Heres a tip to remove the paint from the tires. Go to a Lowe's or HD or any hardware store and pick up a bottle of some stuff call Goof Off. Take that and put it on a rag and wipe it down. Gets the tires nice and clean and takes any gunk off that might be on it too. And if you should do another one take the tires and deflate them till you can almost break the bead and take masking tape and mask off around the rim. That way you dont have to take the tire off and worry about the tire guys scratching the new paint and keeps the paint from getting on the tires.
Just thought it would be a helpful hint!