No problem, jheem. Like a lot of colloquialisms, there's roolz an' there's roolz. You might refer to some absent person as "me china", as in "I saw me china the other day", although these days I think that's probably taking Cockneyism to extremes. But calling someone "me old china" is still seen as "normal", although the tone of voice determines whether the addressee is really your mate or someone you're about to give a bit'uv GBH to. "Me old china" seems to have successfully made the perilous transition from being an expression of pure cockney rhyming slang to an everyday role in Estuary English. I hear it used a lot, and not necessarily by people from the London area.