ALL CREDITS TO MINDACOS!

Vivid Plasma Surgeon's Stahlhelm

Sold with a Midnight Whirlwind Burstchester(20.5 Keys) for a Disco Beat Down Deep Cover Operator(52.5 Keys) and 8 Keys(40 Keys total)

https://backpack.tf/profiles/76561198100877472#!/compare/1509840000/1509926400

Sold for an Australium Pro KS Sniper Rifle(~31 Keys) and an Australium Pro KS SMG(~8 Keys)(39 Keys total)

https://backpack.tf/profiles/76561198074924284#!/compare/1508025600/1508198400

Sold for a Burning Flames Base Metal Billycock(34.5 Keys) and a Stormy Storm Buckaroos Hat(12.5 Keys)(47 Keys total)

https://backpack.tf/profiles/76561198156255538#!/compare/1511395200/1511481600

39-47.