I agree with Joe. I had a chip right in the center of the bed of my machine, right underneath the arm. How it got there, I'll never know. It always caught my eye. I finally went to the local train/model/hobby shop and picked out the closest beige for my Rocketeer. I tested the Testor paint underneath the machine first to see if it matched or if I'd need to buy another color to mix. Luckily, it was pretty close. I used someone else's suggestion and used a toothpick instead of a brush. I put a tiny dot of paint in the chip and let it spread outward. This didn't fill the chip completely, so I did it again, also with a tiny amount of paint.
After it dried, you could see that the paint was slightly different, but I wasn't trying to match exactly, I just didn't want that chip to constantly catch my eye, being in the center of the bed. It was good enough that I touched up a couple of other chips around the edge of the machine too. That was a year ago and, until now, I hadn't thought about that chip again.
Tate