At half an inch across I would tend to use lacquer rather than superglue, particularly if it is down to the colour coat. I don't know how easy you will find it to obtain nitro lacquer, particularly in small quantities, some nail polish is nitro though a hunt through Boots found only acrylic nail polish. It might be worth experimenting with acrylic though, in theory it should work fine and won't do any damage to the existing finish. Same procedure, just paint or drip it into the hole, let it dry properly (at least a day with nitro or you end up with too much shrinkage a few months down the line) then repeat until you are slightly higher than the original finish, flat and polish. If you need any advice on the flatting and polishing process, let me know.