I have done domestic repairs, philips supplied me with parts and schematics, sony didnt want to know, hence my comments (in the uk main dealer repair centres will also supply parts, or used to), philips also have sent me datasheets and sample devices for projects I've been involved with.
You answered my point in your own post, a datasheet for a remote or decoder ic often has protocol info, I presumed that this would have been sufficient for the op, rather than a specific datasheet just on the protocol, maybe I misunderstood that one.
I'm in the uk too, profile edited.