Here we go! Got the .pk1 files zipped up and named the same way the EventsGallery would expect them https://github.com/projectpokemon/EventsGallery
Toys R Us Blue Version OT Gary YOSHIBA Mews.zip
You may be totally right, Looked in the earliest and latest box and might be mistaken! I plan to run a PKHeX.Core script later to turn each Mew into a .pk1 file, that will tell us for sure.
Here you go!
I can confirm the SHA-1 sum is d7037c83e1ae5b39bde3c30787637ba1d4c48ce2
There are random pokemon in the party from an OT named TOR. Must have been whomever last traded for mews, 3 of them
It looks like Mew TID's range from 57440 to 59428