There are three mix-and-match styles to the supplied STL files: metric vs. imperial, narrow vs. wide, and long vs. short. The significance of these three styles are,
metric: lead spacings in increments of 2 millimeters
imperial: lead spacings in increments of 0.05 inches
narrow: for small resistors whose bodies are no longer than 6.75 mm (0.25 inches)
wide: for medium resistors whose bodies are no longer than 10.50 mm (0.40 inches)
long: a long tool with lead spacings up to 40 mm (1.5 inches)
short: a shorter tool with lead spacings up to 30 mm (1.0 inch)
The two OpenSCAD source files are nearly identical with the only difference being that one has settings for metric units whilst the other imperial. As the files are fully parameterized: it is easy to change the increments, dimensions, spacings, widths, etc. of the tools by editing the OpenSCAD files and then re-rendering the tools.
The author marked this model as their own original creation.