The Junk is, well... junk. 10 guns of 12lb and maximum crew 94 make this also not very impressive as a "pirate boss ship". Even Golden Hind wouldn't find that too hard to handle, less of a challenge than most of the ships I've been raiding. "PiratBrig50" is still a brig and therefore not all that scary either.
If I can figure out how to re-texture a ship or if anyone else wants to do it, a modified version of "FleutWar" has possibilities. At least then the early Mefisto is not just yet another variant on a theme of Fast Galleon (there's the basic Fast Galleon, which is also now used as Will Turner's ship in early periods; the general Fast War Galleon, used by France, Spain and pirates; and the specific pirate one used by Roche Brassiliano).
If I can figure out how to re-texture a ship or if anyone else wants to do it, a modified version of "FleutWar" has possibilities. At least then the early Mefisto is not just yet another variant on a theme of Fast Galleon (there's the basic Fast Galleon, which is also now used as Will Turner's ship in early periods; the general Fast War Galleon, used by France, Spain and pirates; and the specific pirate one used by Roche Brassiliano).