mwaoaa_art’s extended/altered artworks give a pretty good idea what some cards might look like if they would have been full arts. Here these three promos for example:
Some other nice ones she did semi-recently:
I could actually link dozens of amazing artists like her who make extended/altered artworks, since I used to collect them for the Base Set Pikachu: Quuador's Collection - All 10 Sealed Moltres! :D - #693 by quuador.
Although I agree with the WotC Moltres promo as a card I’d love to see as a FA card.
Greetz,
Quuador