These paper models are the Iron Hands and Iron Warriors Dreadnoughts, based on the game Warhammer 40K, the papercraft was created by Patoroch. There are other Dreadnought paper models at the site:
Warhammer 40K – Dreadnought Mk I Free Paper Models
Warhammer 40K – Chaos Dreadnought Walker Free Paper Models
Warhammer 40K – Mk IV Furioso Dreadnought Free Paper Model
Warhammer 40K – Ultramarines Dreadnought Mk. V
Warhammer 40K – World Eaters and Blood Angels Dreadnoughts
Warhammer 40K – Chapter Dreadnought Free Paper Models Part 1
Warhammer 40K – Chapter Dreadnought Free Paper Models Part2
Warhammer 40K – Dark Angels and Alpha Legion Dreadnoughts
Warhammer 40K – Dreadnought III Free Paper Model
Warhammer 40K – Imperial Fists and Death Guard Dreadnoughts
The Iron Hands are a Loyalist Space Marines Chapter and one of the original First Founding Space Marine Legions created from the gene-seed of their martyred Primarch, Ferrus Manus. Like the other Loyalist Astartes Legions, the Iron Hands would later be divided up after the Horus Heresy into multiple different Chapters, as required by the Codex Astartes, although one Chapter of the original Legion remained known as the Iron Hands and is described below. Although unwavering in their faith in the Emperor of Mankind and his dream of human unity as embodied in the Imperium of Man, the Iron Hands also believe that human flesh is weak and easily corruptible, and strive to replace their organic bodies with more "pure" bionic substitutes, thus closely emulating the faith of the Adeptus Mechanicus' Cult of the Machine.
The Iron Hands were born as the X Legion of Space Marines, engineered by the Emperor of Mankind to bring his light to the long lost human colony worlds scattered across the stars. When the Horus Heresy first erupted and plunged the newborn Imperium into a galaxy-wide civil war, the Iron Hands Legion was too far from Terra to intervene directly in the climactic battle of the conflict. Their Primarch Ferrus Manus was enraged by the weakness of those Legions who fell to Chaos, particularly with his closest brother amongst the Primarchs, Fulgrim of the Emperor's Children, and by his own inability to face the Traitors. Ferrus Manus gathered together his most Veteran Astartes and departed for the Istvaan System. It was during the Drop Site Massacre of Istvaan V that the Iron Hands, the Raven Guard and the Salamanders Legions were ambushed by the Traitors led by the Warmaster Horus, and though the three Loyalist Legions fought with extraordinary valour, Ferrus Manus himself was lost, beheaded by Fulgrim's Slaaneshi daemonblade which he had recovered from the xenos world of Laeran. While the Traitors declared their Primarch dead upon the blasted wastes of Istvaan V, the current Iron Hands Chapter refuses to accept this, for the Primarch's body was never recovered. For over 10,000 Terran years, the Sons of Ferrus Manus have stoked their burning hatred, drawing strength from this inexhaustible well of rage as they await their lost Primarch's return.
The unique identity of the Iron Hands is forged by their belief that all flesh is inherently weak, for it is subject to mortification, decay and temptation and is thus a weakness that must ultimately be purged if the Chapter's Astartes are to best serve the Emperor. This is a belief most probably rooted in the experiences of the Horus Heresy, but the inherent character of the people of the Chapter's homeworld of Medusa, with their stoicism and patient forbearance, also plays a part. Following the apparent death of their Primarch at Istvaan V, the surviving members of the Legion returned to their homeworld and fanned the coals of hatred that would endure across the millennia. The Iron Hands chose to isolate themselves from many of their fellow Astartes Chapters after the Second Founding and slowly became bitter recluses, wielding their anger as a protective shield against a universe of growing weakness and insanity. Unfortunately, in time, this hatred was directed at all outside the Chapter. The Traitors had renounced their oaths to the Emperor and shed the blood of their brothers, but the Loyalists had also allowed this to happen, and even the Emperor had fallen after defeating Horus. The Iron Hands harbour a special hatred for the Successor Chapters of the other two Loyalist Legions that fought with them at Istvaan V, for they believe that if those Legions had been stronger and continued to fight rather than retreating, Ferrus Manus would not have been lost and the Heresy might have ended there. This belief defies all facts to the contrary.
The Iron Warriors are one of the 9 Traitor Legions of Chaos Space Marines that turned to the service of Chaos during the Horus Heresy and now fight to overthrow the Imperium of Man. The Iron Warriors, who were originally the IV Space Marine Legion, specialised in the breaking of sieges and assaults on static fortifications, which made them great rivals of the Imperial Fists Legion, which was said to construct the greatest static defences in the Imperium. It was this rivalry between the Legions, and between their Primarchs Perturabo and the Imperial Fists' Rogal Dorn, that helped turn the Iron Warriors to Chaos. Like the members of the Adeptus Mechanicus and the Loyalist Iron Hands Chapter, the Iron Warriors have a strong predilection for replacing parts of their body with cybernetic enhancements. When struck with a mutational "gift" from the Ruinous Powers, most Iron Warriors simply cut off the mutated appendage, if possible, and replace it with a mechanical one. [Source: wikia]
You can download the paper craft model here: Warhammer 40K - Iron Hands and Iron Warriors Dreadnoughts [Box] [Gavitex]