Being far from an expert on these marking, i believe the P.O.D. with inspector letter is pre WW2 and the BA - WL is a WW2 inspection stamp. I have seen the following P.O.D. M, P.O.D. D . I have some data on a Rock Island 196xxx serial range with 6-11 dated barrel marked P.O.D. B BA-WL. My P.O.D. is on a four digit Springfield with SA 1918 dated barrel.
It would be difficult to prove if your rifle came back from the Philippines after WW2, although it has been said that some rifles (M1903) were imported from there during the 70's?
Attachment 124576