Hothead

https://backpack.tf/item/6982628445

Sale 1) Sold + ~34.5 Keys of stuff for an Aces High Villain's Veil + ~31 Keys of Stuff

https://backpack.tf/profiles/76561198062779791#!/compare/1557360000/1557792000

Using for the Veil.

https://backpack.tf/item/6990179046

Sale 2) Bulk sale

https://backpack.tf/profiles/76561198055544256#!/compare/1554508800/1554595200

Sale 3) Bulk sale

https://backpack.tf/profiles/76561198060828964#!/compare/1551571200/1554595200

Sale 4) Sold for a Burning Flames Modest Metal Pile of Scrap (95 Keys) + Green Confetti Safe'n'Sound (12 Keys) + ~1 Key of Items

https://backpack.tf/profiles/76561198068732040#!/compare/1555286400/1555372800

https://backpack.tf/profiles/76561198132527164#!/compare/1555286400/1555372800

95 + 12 + 1 = 108 Keys

Sale 5) Looks like it sold for a Cloudy Moon Prussian Pickelhaube + Stormy Storm Blast Defense

https://backpack.tf/profiles/76561198132527164#!/compare/1555286400/1555372800

https://backpack.tf/profiles/76561197971403645#!/compare/1555632000/1555718400

Sale 6) Bulk sale for a Burning Flames Crone's Dome

https://backpack.tf/profiles/76561197971403645#!/compare/1556409600/1556496000

https://marketplace.tf/items/30993;5;u13 - Sold for $198 twice when Keys were $1.78 each time

198 / 1.78 = 111.23, which rounds to 111 Keys