Were there copies of any of the Books of Maccabees (and/or Megillas Antiochus) found amongst in the Dead Sea Scrolls?
According to Wikipedia, no.
According to Vermes, every book of the Tanach was represented by fragments except Esther, probably because it involved a Jewish woman intermarrying with a gentile king. The reason the already-written Maccabees book would definitely NOT be found there is that the Dead Sea sect was absolutely opposed to the Maccabean/Hasmonean High priests. The background of the "Damascus" document and a bunch of their other writings makes it appear that the sect split off from the "mainstream" Jews precisely because non-Zadok decended High Priests were serving in the Temple. After Onias the High priest was murdered, first the Seleucid Kings in charge installed some, and then the Maccabees themselves — non Zadokites — took over the High priesthood. The Dead Sea guys withdrew to Qumron, probably to maintain purity for themselves and their leaders, who were apparently Zadokite priests. The Book(s) of Maccabees would have been absolutely anathema to them, and they would neither have copied nor kept copies of it.
There are several books called "Maccabbees," and they're pretty much unrelated to each other. They also written across a wide time span. Only the first book (IIRC) would have been composed in time for the Dead Sea Sect to have it in it's collection. But since they were an isolationist sect who weren't too pleased with the monarchy and the priests, it makes sense that they would not have preserved a book which glorifies both.