History 1: https://backpack.tf/item/8372776383

50 keys pure:

https://backpack.tf/profiles/76561198318170190#!/compare/1601078400/1601164800

https://backpack.tf/profiles/76561198060874702#!/compare/1600992000/1601078400

Buy order to confirm it: https://bot.tf/stats/listings/4WXDDKL5

History 2: https://backpack.tf/item/8337770648

Untraceable sale (none of the keys match)

https://backpack.tf/profiles/76561198003935476#!/compare/1599523200/1599609600

https://backpack.tf/profiles/76561198069137737#!/compare/1599523200/1599609600

Buyout was 100 keys https://bot.tf/stats/listings/MGLQ3L77

Buyer didn't have a buy order

Sale on Marketplace.tf https://marketplace.tf/items/tf2/30922;5;u3036

(UNTRACEABLE) July 24 2020: $99.95 (key=$1.94, 51.52 keys) ~52 keys

We have 50 and 52. Not sure if the seller at 100 keys actually sold at that but if they did, it would be considered an outlier

Going with 50-52