Historical clue formulations

• Shell, maybe — 2021-01-30
• Door or window frame — 2020-10-16
• Window holder — 2011-12-09
• Sausage part — 2009-03-01
• Cover — 2007-05-06
• Checking out, as before a robbery — 2006-06-12
• Checking out, as a joint — 2006-01-23