Each card uses the original cover art of a different source book, stretching all the way back to the monochromatic art on Dungeons & Dragons Supplement I: Greyhawk from 1975, which is depicted on the white card Fell the Mighty
This reprint also appeared in Ursula's Return with the same text, so we know the ceiling
You can find showcase legendary cards in Draft, Set, and Collector Boosters as well as within products that contain those boosters
Salvage Scuttler: Great effect, but a little too heavy
The name of at least one face must be written on the substitute card, and any other information visible on either face of the card may also be written
What was supposed to just be a backstage meet-and-greet turned into an "unexpected" sale, when Post Malone started asking what the current bid price was