Mmontoro,
You could see some discussions on Malela blades plus examples at the folowing earlier threads which may answer some of your questions. Broadly, the main characteristics are the pair of fullers along the blade plus that the blades do not have pamor.
http://www.vikingsword.com/ubb/Forum1/HTML/000969.html
http://www.vikingsword.com/ubb/Forum1/HTML/000978.html
http://www.vikingsword.com/ubb/Forum1/HTML/002097.html
BluErf does make an interesting point in that the finer aesthetics of N Malayan pieces do not seem to be evident on the piece in question. Put this piece amongst a group of N Malayan Malelas, I think it's not difficult for one to pick it up as an odd one. The ada-ada (spine) is also broader but at least for now I think the piece looks nearest to a Malela.
But as always I defer to the more knowledgeable members and learning along the way...