1
The original Golden Idol was tracked down in Hawaii by Brandon Allinger, who placed a newspaper ad seeking props from Raiders of the Lost Ark; it retains its green resin base after the sputter-coat gold plating wore off, and is one of the few versions with real baby doll eyes inserted.
2
Two distinct versions of the headpiece of the Staff of Ra existed on set: an earlier 'Raven Bar' version used for most filming, and a later, more detailed sculpt made specifically for close-up insert shots — the existence of two versions was only recently confirmed publicly.
3
The Holy Grail cup screen-matches to the scene where Indiana Jones drinks from it; it is an English church sacrament vessel that was rented by production, cast, and then returned — Lanigan later tracked it down at auction.
4
Adam Savage details the sputter-coating process — metal is melted in a vacuum to deposit an angstrom-thin metallic layer — explaining why C-3PO costumes and similarly coated props degrade as plasticizers leech out of the resin and push the coating off.
5
Lanigan recounts identifying the screen-matching Sankara stone from Temple of Doom in a Profiles in History auction catalog where it was not even described as a match, making it the only known matching stone outside of Lucasfilm.