Actually, if you want to do that, I'll throw in a bonus of a clone of the Flying Pikachu from the 2012 VGC held August 12, 2012. Thing is, there'd be a third tacked on which would only come AFTER you get the Magby back (and for that one just send a junker, I have the entire Dex covered; I do accept DW however).
I'd be willing to clone the Shiny Magby if you want to take the deal from both of us. The other person can have the original. I have both Mew and Mewtwo, so figure out what that person's giving you and I have the other covered. I was at a concert in the evening or I'd have been here sooner.
Is the Shiny Magby legit.? I have a Mew and Mewtwo. The bad part? You can't really use them in battle until you've gone a little ways, moreso with Mewtwo (Lv.70 I think and thus requiring six badges just to use for one level, then seven badges to keep using it). Mew, meanwhile, could be used after three badges in the same method as Mewtwo (two for Lv.30 battling) as long as it doesn't grow too fast.
So thus I'll suggest Mew (besides, without an Action Replay hack on the GBA Emerald, you can't get it since except via Event). It will be a clone. I could also do Mewtwo, but I highly recommend not trying to use it (yet). Neither, BTW, shows up in your Dex until you have the National Dex, so don't look for their entries until after the E4.