I used it to repair lugs/threads on a crankcase for an AMC timing cover a couple of years ago, and it did do it. But I found it hard to use in areas which had been oily over the years and I didn't find the 'abrader' an easy tickling stick to make things do what '54A10 so accurately describes although it worked well under test on clinically clean bits beforehand. The colour didn't bother me being on the inside as it were, but it's a bit different from the parent metal. In its favour, it took to the alloy, it drilled, it tapped and it is still holding some 2BA screws where they should be after a good few thousand miles - so it's tough enough to take an absurdly small fine thread (that BSA would never have used for such a thing).
Haven't tried it for cosmetic repairs though - MG's pix are better guides!