Hello n2s,
very nice knife you have there!
When you boring it I would be more as glad to take it from your hands!
I am nearly sure that it is a Thai knife, Southern Thailand to be correct. It's a monk blessed knife I think. The inscription is a yant prayer inscription from a monk to protect the owner and is written in Buddhist Pali.
I think it has the maha yant of Luang Por Derm engraved on its blade IMVHO. Luang Por Derm died in the 50s last century so your knife is minimum old like this.
It could be that the blade is worked from lek namphee, when you will etch the blade and it get a dark bluish colour it is worked from this special steel. I have byself a knife from this steel, when I will find the time I will post pictures.
The workmanship of your knife is very good so it could be that it belongs once to monk. Again, very nice knife, I am a little bit envious!
Regards,
Detlef