Historical clue formulations

• Chopper parts — 2025-06-18
• Turning points — 2023-04-28
• Whirlybird whirlers — 2022-08-07
• Disc brake components — 2020-08-16
• Spinners — 2016-06-19
• Whirlybird whirlers — 2016-03-26
• Whirlybird whirlers — 2003-02-23
• Chopper parts — 2001-06-29
• They take turns — 1998-02-13