I've used 3M Spot N Glaze for years. Comes in three types, Red, Blue and Green and thins with laquer thinner. Differences are color and drying time, with red (which I prefer) taking a couple of hrs to dry and green just a few minutes and the blue is in between. I have noted that the faster it dries, the more it shrinks. You should be able to get it at any well equipped auto supply store or automotive paint store. One word of caution however, the last tube I bought (about 6 months or more ago) I was informed that they had been told it was going to be discontinued (so I bought 2 tubes, which should be a 10 to 16 year supply)