Hello Ian,
why you think that it wasn't made in Luzon? A very similar example from my collection with the same handle style was discussed here:
http://www.vikingsword.com/vb/showth...ighlight=luzon
This swords are described by the Macau exhebition as matulis but it may be not the correct name, sansibar is a other name which could be possible.
A polish and etch could bring out a nice lamination of the blade.
Nice catch and interesting with the mark at the handle.
Regards,
Detlef