Hello. This thread is great!
Sorry, I'm from a country with Mount Fuji. My English is very childish.
Well, I found a method to replace the "client.bin" of the "Ruby_And_Sapphire_Rev.gcm" with "sample0519.bin" & to receive the Negaiboshi Jirachi(GC -> GBA).
An actual machine is also all right.
If Start.dol's country code in the "Ruby_And_Sapphire_Rev.gcm" is USA and use the USA-Cart, WISHMKR's client.bin & client.2003_1112.bin did work.
Of course, In that case, you don't need change it for the "Ruby.tgc" and the "pokedownload.tgc".
Probably the issue that Broken GCM