I'm with Tim 100% on this one. Spanish colonial. The crosspiece looks spot-on to a naval dirk that I have that I suspect is Portuguese/Brazilian. Here's the old thread, the dirk in question at the top above the British ivory hilted piece. The horn grip resembles those found on espadas and that Brazilian cutlass I mention so often...
http://www.vikingsword.com/vb/showth...5&page=2&pp=30