I do not know about phillipine items but I have seen historic pieces with aluminum fittings before. Such as german pieces from the 1900 till wwII It seems that for a time it was not looked on as a "cheap metal" like it is today. Here is a luftwaffen sword made by solingen with aluminum fittings
http://snyderstreasures.com/images/g...affeeSMFHF.jpg
Like you though it always raises suspicion