Historical clue formulations

• Bad material for a silk purse, proverbially — 2024-03-31
• What you can't make a silk purse out of, proverbially — 2023-06-18
• Unlikely source of a silk purse — 2019-02-28
• Low-quality material, in a saying — 2016-01-31
• You can't make a silk purse out of it, they say — 2013-06-03
• It's not a silk purse source, it's said — 2008-10-19