Historical clue formulations

• Gadget — 2013-06-24
• Thingamajig — 2011-05-23
• Gadget — 2009-10-11
• Whatchamacallit: Var. — 2009-05-17
• Doohickey: Var. — 2006-03-06
• Doohickey — 1996-06-16