It hasn't disappered -- it will be preserved because it's important. The tooling will exist in automotive museums and the expertise will reside in engineering h

It hasn't disappered -- it will be preserved because it's important. The tooling will exist in automotive museums and the expertise will reside in engineering historians and engineering academics -- the first tractor engines are generally still the learning tools for many undergrads. That knowledge just shifts from working proffessionals to another group in society.