I've just restored a Wyvern 202 and it occurred to to me that I could use the blog to remind anyone new to these pens that the section is a left hand thread.
I've seen a few of these pens with severely gouged sections caused by the unwary attacking the section with jawed tools. When turned the right way these pens usually come apart easily with a little gentle heat, I use a hairdrier.
It's also worth remembering that the pen also has a breather tube, not a common feature of button fillers.
