Balinese Keris

[David]

Hi Martin. Welcome to the forum.
I assume you are asking about what kind of sheath this should have? A warong means "stall" in Bahasa Indonesian, "tavern" in Javanese. You may have been thinking of the Javanese word wrongko (also spelled wrangka or warangka). Or maybe you meant "Sarong", which is sometimes used in Bali to mean a sheath.
If i am correct that you are referring to the sheath then there are a few options for dress, but i would say that the Bali version of the standard everyday dress (called gayaman in Java, the Balinese name is eluding me right now) would probably work best for you.
Also, the hilt rings in Java are mendak. In Bali they use a somewhat different style of ring called wewer or uwer. It should not be to difficult for you to find a wewer for sale on eBay or some other similar site. The sheath will be harder to come by. Sometimes i have seen used sheaths for sale on eBay that can possibly be adapted to fit your keris.
This seems like a decent blade and does seem to present as Balinese, though the greneng seems a bit strange me for 19th century Bali blades. Though i can't think where else i would place this blade.