WoW just wow...great looking notes! Question why does the 100 Pesos have a serial number but not the 500 Pesos, no dates either?
No. The 100 peso is from the first series of Philippine JIM all of which had serial numbers. The second series of Philippine JIM notes were printed without serial numbers on all the denominations. Why? Probably because it was cheaper and easier (remember, this was wartime) and the Japanese were not too concerned about accountability.
Most of you probably already know this, but for those who may not, the tiny kanji (Chinese) characters written in "seal script" at the very bottom of the obverse sides of these notes translates as "Japanese Imperial Government". Gary