Posted 07 July 2015 - 22:58
The oils of the perfume have penetrated the plastic of the section. They were "applied" in a somewhat concentrated form from the hand in question. They now leave the pen by diffusion, both as oily molecules continually coming to the surface, and as the individual odorant molecules you detect evaporating and diffusing into the air. Absorbant and adsorbant materials such as baking soda, kitty litter, etc., can only remove the molecules at the surface or in the, and prevent them from returning to the pen. While the perfuming may have been accomplished in a relatively short time, alas, the "de-perfuming" will take longer.
Perfumes are designed to become more volatile at near-body temperature, which is why women usually prefer to evaluate a fragrance after application to the body. You might take advantage of this by string the section and cap, packed in baking soda, in a warm place -say, about 90 degrees F. It is about the only thing that will speed up the dissipation if the odor. (Solvents, if course, can extract oils but are not a good option here.)
The only other possibility is to use a counteractant such as Fabreze (spelling?) odor neutralizer. Place the pen section and cap in a container with a paper towel saturated with Fabreze liquid. There is no need for direct contact if the active ingredient in the Fabreze diffuses from the liquid into the air and thence onto the pen. I can't see why this would be detrimental to the pen parts, but it is all only an educated guess from a former chemistry professor.
Good luck! I wonder if the previous owner intended to attach a favoredfragrance to the pen, as an alluring touch?