Your search for "Dimir Signet 260" revealed the following:
Dimir Signet (RAV) from Ravnica: City of Guilds, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Greg Hildebrandt Card Text:1, T: Add UB to your mana pool.
Dimir Signet (Foil) (RAV) from Ravnica: City of Guilds, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Greg Hildebrandt Card Text:1, T: Add UB to your mana pool.
Dimir Signet - Dan Frazier is Back: Allied Signets (SLD) from Secret Lair Drop, available at 401 Games Canada. Rarity: Rare Finish: Normal Artist: Dan Frazier Card Text: Dan Frazier: Allied Signets1, T: Add UB.
Dimir Signet - Dan Frazier is Back Secret Lair (Etched) (SLD) from Secret Lair Drop, available at 401 Games Canada. Rarity: Rare Finish: Foil Artist: Dan Frazier Card Text: Dan Frazier is Back: The Allied Signets1, T: Add UB.