Oswald Fiddlebender is a rare Legendary Creature — Gnome Artificer card from Adventures in the Forgotten Realms (AFR), collector number 304. Current market price: $2.21 (foil $3.02), TCGplayer market prices via Scryfall.
Magical Tinkering — {W}, {T}, Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.