exsonic

So... I want to make a Shiny Mew, but the one received by the 10th Anniversary Event (Heart Gold / Soul Silver) CAN'T be Shiny, so I'm trying to make it a legal Shiny by making it looking like it was from Hoenn. For my luck I got on a trade a REAL normal Mew that was transfered from Ruby. The part that got me is the Common GBA Event (Restricted). How can I reproduce that one? Thanks in advance '-'