Please feel free to surf the following links as they are for your convenience.
They include additional information, parts, 4x4 clubs and more pictures.

MILITARY VEHICLE PRESERVATION ASSOCIATION - International organization for military vehicle enthusiasts, historians, preservationists and collectors interested in the acquisition, restoration, preservation, safe operation, public education and display of historic military transport. - Additional information on the M274 Mechanical Mule. - The ultimate 4X4 page. - M274 Mechanical Mule page.
Military Mule, ATV - Tons of information here! Great pictures.
Mule Page - Mechanical Mule Miniatures
Wild Willys - Machine Guns, Jeep Willys & Mules.