OK, you asked ...!
Unstyled WC's (square front radiator) were made from 1933 through 1938, styled WC's (rounded grill and teardrop-shaped gas tank) were made from 1938 to 1948 (The styled version was designed by Brooks Stevens of Milwalkee). They were sold on steel wheels or on rubber tires. The gasoline version produced 29.93 hp with a 201 cubic inch, 4 cylinder engine (there was also a distillate or tractor fuel version, and the very first WC's had a smaller engine).
It was intially called the Model W All Crop in 1933 and was later called the WC in 1934. Much of this is from Norm Swinford's "A Guide to Allis Chalmers Farm Tractors," ISBN 0-929355-78-4. The book doesn't say but it was probably built in West Allis, Wisconsin. Other books by Norm Swinford and CH Wendell have a *lot* more info ....!