Basically an Aviation but with triple sec in place of maraschino and lime instead of lemon juice. Gaz used lime juice because he didn't have any lemons...
Grappa is such a poorly regulated liquor so it depends. In my experience they can be anything between a distillate that includes slugs, leaves and a grape picker’s lost glove, to a lovely, smooth brandy. Some do have a bitter, stingy flavour profile that will not work well with citrus. If that is the case with yours, I would first try just a tad of sugar syrup.