Right there's 14 of these, but surprisingly they rarely hit the market so sales are kinda limited. Any help is welcome.

Sale at 52 keys:

https://marketplace.tf/items/631;5;u110

Sold for $109.99; keys are worth $2.10.

Sale at 33 keys:

http://i.imgur.com/ITIkwTt.png

http://steamcommunity.com/market/listings/440/Unusual%20Hat%20With%20No%20Name

Sold for £66.17; keys are worth £2.00 on SCM. Bought within a day of it being listed, calling it a quicksale.

4 month old supportive sale: http://backpack.tf/profiles/76561197972648787#!/compare/1480636800/1481155200

Sold for the Scatter which sold for 45 keys: http://backpack.tf/profiles/76561197972648787#!/compare/1480550400/1480636800

Found that on the BF KE suggestion of all places.

I am 90% sure that the SCM sale on 14th April was also a Slumber HWNN but I have no evidence of the effect so can't include it (I've been watching them for a while).

If anyone has more proof, supportive or otherwise, please drop it below or by all means counter me. Cheers.

One on the classifieds listed 16 hours ago at 105 keys: http://backpack.tf/item/5185030277

Worth keeping an eye on.