The storage box in Emerald is basically the exact same thing as in RS, except you can Move Items inside of those boxes.
I play Pokemon Emerald, LeafGreen and Sapphire still. I am trying to get the National Dex completed for all 3 and breeding for my Competitive Pokes in Emerald.
A few of my friends where I live still play their Sapphires and Emeralds. Only my sister in the whole village has Ruby, and she still plays that.
I don't have Pokemon Box. I wish I did. I got a credit card a few years ago just so I can get it, but as soon as I got the card, the Pokemon Box wasn't sold anymore. Now I can't find it without it being 150+ Dollars.
For the Mew: Try checking it's stats, and see if they have these stats:
Code:
Mew Level 10 Stats:
HP Att Def Sp.A Sp.D Speed
-----------------------------------
43 28 28 28 28 28
Those stats are assuming a Neutral Nature. For the Natures that have +/- in their stats, follow this:
HP: 43
Will always have Max HP of 43. Natures do not affect this.
Other Stats: 28
+ Nature: 30
- Nature: 25
If your Pokemon has those Stats, that shows possibilities of 31 IVs in the stats. Just put the Pokemon with the highest stats you can find into a single box, line them up according to their stats from highest to lowest in the next box after that and then check the stats according to the 31 IVs.
I might not be 100% right on that, I still haven't written my IV guide for my forum, but I am pretty sure that's correct.
Any corrections, post it replying to the stats thing. Quoted reply.
Edit: Try going here to find EVs of Pokemon.
http://www.metalkid.info/Pokemon/OnlineProgram/Calculators/IV.aspx
That is currently the best IV Calculator that I can find.