One thing that neds to be taken into consideration the older toolong was designed to support one version of a kit. If that was to be changed then that tooling had to be irreversiblly modified. Newer tooling Revell 32 fords, 57 checy , and 57 ford were all designed to allow different versions by changing the body segment of the tooling. The multiple version tooling is a necessity becuse of the much lower volumes being produced.