Historical clue formulations

• Doohickey — 2017-04-25
• Many an infomercial offering — 2016-05-20
• ... #6 — 2015-12-21
• Thingamajig — 2013-05-12
• Thingumbob — 2009-11-05
• Potato peeler, e.g. — 2000-06-14
• Device — 1997-05-11