No, not too far out with India. But, to be honest, if it wasn't for that PF number I wouldn't have known either. I have seen a version of the mark beneath the War Department arrow, I have a couple on bayonets in my collection, but I haven't seen that particular version before, which as you say, looks quite Indian.
I was quite correct about Burma using the PF marking, but, evidently, so did Ireland! I was thinking about this and remembered an Irish No.9 bayonet that I have, and finding some pictures of it, lo and behold, there is the PF serial number. However, following that a perusal of Graham's book Spirit of the Pike, says on page 231, that both countries used the PF mark. However, the example shown there as being from Burma, also has the other type of the stamp below the WD arrow, only that in the book is the MR and arrow, that I have seen before and have on a couple of bayonets in my collection. Same placement, and very similar looking. maybe the same marking, but in local script?
So, I'd still go for it being Burmese!
This is my Irish example:
Note the absence of any mark below the WD arrow on this Irish example.
Interesting, Graham only mentions Burma and Eire using the PF prefix, however, the great thing about collecting is that there is always new information coming to light!
The very similar markings on the bayonet, or two that I have are similarly placed, but are the letters MR with the arrow between them, not letters and numbers like these. Perhaps also an inspectors stamp? I seem to recall somewhere that they were an arsenal in either India or Pakistan, but due to the wars there, it has changed nationality.
Both the illustrated examples in Spirit of the Pike are also serial numbers in the 300.000 series if this is any help?
By the way, when looking for that fourth picture, my caption shows 'Sensitive content, not recommended for those under 18' ? Perhaps they are worried that young lads might discover something interesting and start seriously collecting !