Caterpillar Sixty, 1936 Caterpillar Forty with a 1940 Terracer, a 1945 Cat D7 dozer, a 1952 International TD24 show they can still work.

This medium size-class dozer weighs in at 29,259 pounds and is powered by a Cat C4.4 engine producing 130 horsepower, mated to a hydrostatic transmission. The D6K2 was part of a model family that ...