I am not sure the Philippines is accurate. The NS ones I've seen are Chinese subject matters and I believe the writing on them is Chinese as well. Here is an interesting web page discussing the distribution:
http://www.jimsburntofferings.com/adschinapirate.html
If it was a P.I. issue, I would expect the language to be English or Tagalog, like these P.I. issues:
The Asian and African-distributed card sets are an area ripe for further analysis. There were a lot of cards that made their way around the world in the prewar era and how and why some of them got there needs explanation.