Might need some help organizing and developing a timeline, but I wanted to make a list of all appearances and uses of the Mew we know from our Black Star Promo.
This thread will be a dump with a short description until I get organized.
Posters/Flyers/Tournament Ads
Nintendo Space World '97 ad (still need translation)
Pokemon TCG League
Mew Present Corner
*Ad for 1999 Event
Sprites
GB1 Released Japan December 18, 1998
GB2 Released March 28, 2001
Honorable Mention: Mew conception Sprite (Idea by Taijiri, creation by Morimoto in the GameBoy game, and revision by Sugimori)

Cards
Mew Fossil Japanese
Released June 21, 1997
Mew Black Star Promo 8 (non holo) & 9 (holo) (League)
8 Release January 8, 2000
9 Released April 2000
Gotta Mew (Glossy Mew from Appendix)
*Released May 1, 2000 Gotta Comic)
Plaques
Awarded to employees year 2000 in UK
Stamps
Shogakukan Stamp
Pokemon Complete Stamp (Shogakukan Mew Promo - need info)
Postcard
Mew Zukan Post card Dated 1997
Sort later
Japanese Fossil Poster (CoroCoro Magazine Insert)