[Oliver911]

DA refers to a Dual Action Sander, also referred to as a Random Orbit Sander. I only suggest PPG because it is a high quality product that I am familiar with and can recommend the product numbers and how the products are used. Glasurit was the original paint supplier to Porsche. These are also very high quality paints, along with many other brands, however I am unfamiliar with them. To answer your next question, touch up on a car of your vintage with original paint is very difficult. The great thing about having a clear coat is its ability to hide blend lines, your car does not have a clear and is most likely painted with a lacquer or enamel that has faded significantly. I would suggest dabbing the stone-chips with lacquer based paint. Then, wetsand with 1500-2000 grit 3M sandpaper and buff to a shine. Good Luck.