History 1: https://backpack.tf/item/4481682265

Dumped to a bot:

https://backpack.tf/profiles/76561198058257901#!/compare/1634947200/1636675200

https://backpack.tf/profiles/76561199059160806#!/compare/1636588800/1636675200

13 keys match in buyer's compare:

https://backpack.tf/profiles/76561199059160806#!/compare/1638576000/1638662400

https://backpack.tf/profiles/76561198189324958#!/compare/1638489600/1638662400

matches buyout https://gladiator.tf/listings/61aa9a95cba109f12b997f3d

History 2: https://backpack.tf/item/5689616657

Sold alongside the buds, Haunted Haunted Hat and Strange Festive Force-A-Nature, can't trace what they sold for:

https://backpack.tf/profiles/76561198051484117#!/compare/1635206400/1636070400

https://backpack.tf/profiles/76561198041100592#!/compare/1634083200/1637539200

History 3: https://backpack.tf/item/9318299622

https://mannco.store/item/440-veno-shock-unusual-taunt-the-killer-solo

$19.98 / $1.72 = 11.62 keys ~12 keys

~~

https://marketplace.tf/items/tf2/30609;5;u3045

$24.99 / $1.84 = 13.58 keys ~14 keys

from Cashew:

"https://backpack.tf/item/9353380734 seller at 11 for 3 weeks"

I'll go with 11-14 for now