Searlock Holmes

http://backpack.tf/item/941838044

Sale 1) Sold + 27 Keys for a Circling TF Logo Dr's Dapper Topper (49.5 Keys)

http://backpack.tf/profiles/76561198214139636#!/compare/1476662400/1476835200

49.5 - 27 = 22.5, which rounds to 23 Keys. Bulky, but supports a drop.

Sale 2) Quicksold for 24 Keys

http://backpack.tf/profiles/76561198080179568#!/compare/1477353600/1477440000

http://www.tf2outpost.com/trade/28564589

Sale 3) Sold + 2 Keys for a Smoking Federal Casemaker (32 Keys)

http://backpack.tf/profiles/76561198117433241#!/compare/1473638400/1473724800

32 - 2 = 30 Keys

Casemaker Mini

http://backpack.tf/profiles/76561198064723321#!/compare/1473033600/1473120000 - Sold + Dead of Night (~1 Key) for a Blizzardy Storm Modest (33 Keys)

Modest Micro

http://backpack.tf/suggestion/5831b687c440455a375a93cf - 33 Keys

Sale 4) Sold for a Duped Steaming Dr's Dapper Topper (24 Keys) + 4 Keys

http://backpack.tf/profiles/76561198146554694#!/compare/1478217600/1478390400

24 + 4 = 28 Keys

Dapper Mini

http://backpack.tf/profiles/76561198146554694#!/compare/1478390400/1478476800 - Sold for 24 Keys