Classifieds: http://backpack.tf/classifieds?item=Gridiron%20Guardian&quality=5&tradable=1&craftable=1&australium=-1&particle=62

Screenshot(s) of Classifieds:

http://imgur.com/KmvTfkQ

<Sellers>

9.85 keys | http://backpack.tf/item/2120726329 | http://backpack.tf/u/76561198304138933 | Listed less than a minute ago

12 keys | http://backpack.tf/item/5138660171 | http://backpack.tf/u/76561198034312547 | Listed 10 days ago [Bumped]

12 keys | http://backpack.tf/item/1965055616 | http://backpack.tf/u/76561198164651434 | http://www.tf2outpost.com/trade/28837755 | Listed 12 days ago [Bumped]

http://www.tf2outpost.com/trade/28848063 - b/o: 12 keys (1 day)

Sold:

http://backpack.tf/profiles/76561198167045406#!/compare/1490486400/1490572800 - sold for Nuts n' Bolts Armored Authority = 11 keys

http://www.tf2outpost.com/trade/28844852

http://backpack.tf/profiles/76561198167045406#!/compare/1489449600/1490313600 - sold for Aces High Tam O' Shanter = 11 keys b/o

http://backpack.tf/profiles/76561198282738743#!/compare/1490313600/1490400000 - sold with 1 key for Dead Presidents Plug-In Prospector = 10 keys

http://backpack.tf/profiles/76561198085966081#!/compare/1489104000/1489190400 - sold for 7 keys (quicksold)

http://www.tf2outpost.com/trade/28818023

http://backpack.tf/profiles/76561198002757046#!/compare/1488931200/1489017600 - sold for Dead Presidents Pugilist's Protector = 10 keys

Mini's:

Nuts n' Bolts Armored Authority:

http://backpack.tf/profiles/76561198110254941#!/compare/1490486400/1490572800 - sold for Nuts n' Bolts Tavish DeGroot Experience = 11 keys

Dead Presidents Plug-In Prospector:

http://www.tf2outpost.com/trade/28844451

http://backpack.tf/profiles/76561198271106202#!/compare/1489968000/1490400000 - sold for Steaming Pyro's Beanie = 11 keys

Dead Presidents Pugilist's Protector:

http://www.tf2outpost.com/trade/28842577

http://backpack.tf/profiles/76561198267189538#!/compare/1490054400/1490140800 - sold for 8 keys (quicksold)

http://www.tf2outpost.com/trade/28841436

http://backpack.tf/profiles/76561198254377432#!/compare/1490140800/1490227200 - sold for 8 keys (quicksold)

http://www.tf2outpost.com/trade/28807634

http://backpack.tf/profiles/76561198296957157#!/compare/1488153600/1488499200 - sold for 9 keys (quicksold)

http://www.tf2outpost.com/trade/28843986 - b/o: 10 keys (4 days)