Japan SC #265 Overprint - Ryukyus?

Hi,

I have a MNH Japan #265 with an overprint that says "Onerubo" in katakana and then the kanji for "North". My catalogue says to refer to the Ryukyu Islands in the US Specialized catalogue but for some reason I am not seeing a space for them in my copy.

I would greatly appreciate if someone could please tell me the story behind this stamp. Why is it considered a Ryukyu stamp? What is its value?

Thank you!

EDIT: Wow, my Japanese skills are failing me. Just realized this is written right to left... So it's North Borneo. Still, information on the stamp will be appreciated. :)

You're reading in the wrong direction. It's a Japanese stamp overprinted 'Kita Boruneo' - 'North Borneo'.

listed in SG as #41 Japanese occupation of North Borneo