Hi Mik
Are these pdf files close to what you want?

It's possible to use a vector program like "Incscape" to set the line style. ( color, width, dashed lines, opacity, etc )

If you want to achieve the same result inside moi, you can use the "dashCurve" script on the 'hiddenLines' generated by the "Make2D4views" command to get the hidden lines dashed effect.
Change the hidden lines style to a darker color (#999999), so it's easier to see.
Then use a white surface to get the line style options. ( It's better to hide the surface edges )
Although, Changing the line width for different curves and styles is not possible.