Here is an FP with an interesting pattern - a cable twist.
It is similar the model in the Parker 180 family which had a more pronounced pattern of black laque over gold- or silverplated brass. (Photos below are courtesy of Tsachi Mitsenmacher.) The 75 twisting pattern seems more tightly spaced than on the 180.
I have seen these 180 models called 'Torsade' in unofficial venues, i.e. non-Parker material. Torsade is a French word for 'twist'.
Take a closer look at this twisting pattern on this 75. Interestingly it is actually comprised of wavy lines that are longitudinal to the axis of the cap and barrel. The peaks and valleys of the waves are what form the appearance of the twisting pattern on the pen.
As you can see the tassies on this pen are dished.