Hothead.

http://backpack.tf/item/4525002675

Sale 1) Sold for a Terror-Watt Deep Cover Operator (55 Keys)

http://backpack.tf/profiles/76561198110459728#!/compare/1487980800/1488067200

Sale 2) Sold + Festive Spec KS Factory New Purple Range Sniper Rifle (10 Keys) + Robo Key (1 Key) for a Duped Purple Energy Waxy (60 Keys)

http://backpack.tf/profiles/76561198313935698#!/compare/1488067200/1488585600

60 - 11 = 49 Keys

Sniper Mini

http://backpack.tf/profiles/76561198240537922#!/compare/1488412800/1488585600 - Sold for 10 Keys

http://backpack.tf/profiles/76561198042011386#!/compare/1488585600/1488672000 - Buyer's Backpack

Waxy Mini

http://backpack.tf/profiles/76561198313935698#!/compare/1490486400/1490832000 - Sold for a Sulphurous Razor Cut (77.5 Keys) + 10 Keys

http://www.tf2outpost.com/trade/28811644 - Capped by the Buyout of 60 Keys

Razor Cut Micro

http://backpack.tf/profiles/76561198313935698#!/compare/1491696000/1491868800 - Sold + 5 Keys for a Death at Dusk Nunhood (90 Keys)

http://www.tf2outpost.com/trade/28873288 - Seller at 70 Keys

Nunhood Macro

http://backpack.tf/suggestion/58e45b22c440451ca11d55a0 - Should be something around 90 Keys

Sale 3) Sold + 9 Keys for a Green Confetti Hong Kong Cone (72.5 Keys)

http://backpack.tf/profiles/76561198240537922#!/compare/1488412800/1488585600 - Seller's Backpack

http://backpack.tf/profiles/76561198267189538#!/compare/1488499200/1488585600 - Buyer's Backpack

72.5 - 9 = 63.5, which rounds to 64 Keys