This papercraft is a 1899 version Armored Steam Tractor “Fowler B5″, designed by jbmodels. The scale of this paper tractor is 1:50. The armoured version of these tractor was made in 1899. Vechicles take a part in conflict in South Africa during Boer War. Fowler was towning three trailers also with amunition or guns.[via jbmodels]
The model is quite simple, only making wheels will be little difficult. The author recommends using 160~180g card paper to build it.