I nearly fell into the polish trap too, but went for the TLA clue instead.
C.G.H. could be Changi General Hospital (Singapore) or Cape of Good Hope.
If Changi, the polsey pagenci could be an anglicised equivalent of an asian language (though it doesn't really sound like it) or perhaps Tagalog? I wouldn't put much store in the spelling (making web searches a bit more difficult) as I suspect the engraver was not fully au fait with English (hence the lower case "g" in C.g.H. (or it could be that BJOW commited a typo). (Lucky he didn't pick BigJarofBees as a username - )
Jhin seems to also be a Hindi word and there are other googled references that come up in Chinese/Japanese? characters.
It probably isn't beyond the bounds of probability that there were Polish patients at Changi General Hospital, though as Singapore fell in February 1942, I can't see that having a compact engraved (in June/July?) would be at the top of someone's priorities.
edited following more reading:
In the context of Singapore, CGH would actually be Civil General Hospital, rather than Changi