I like the fact that you’re trying new things with the pen turning, but… as a writer, I’d be put off by the top design (the myrtle pen). That knob on the business end of the pen would prevent extended writing periods due to severe discomfort to the first and middle fingers.

It might be better to add the decorative details to the top half, instead. In order to remain functional, I’d keep any variations of the bottom have to the slightest flaring (less than 1mm) just before the tip of the pen; otherwise, it starts to lose its functionality. From the end-user’s perspective, it doesn’t matter how good a pen looks if one can’t write with it for very long. Or rather, it matters only up until the point where your fingers cramp.

Merganser
(Woodworking draws some odd ducks (hehe), doesn’t it? Badgers and Mergansers…)