Managed to get my pen apart with my Nicole heat tool. Despite the numerous, dire warnings about destroying pens with these it's actually really easy and safe to do. I keep my fingers next to the area I'm heating; if my skin becomes painfully hot, I ease off. The temperature can be controlled trivially easily, even on a fixed-heat gun, by moving your pen away from the nozzle. You don't want it closer than five inches from the nozzle of an embossing-type heat gun!
As you can see, the joint between pen and section is not threaded after all; all that was in between was a gritty, gray powder which I assume is the mummified remains of either ink or a glue (it could also be machining residue or talc, I suppose.)
The idealized process for disassembling a Peter Pan seems to be:
- Get a dish to put parts in as you disassemble the pen (The components of this pen are unusually, but not surprisingly, small)
- Use rubberized gripping squares to seize the barrel and section. Make sure you grip above the lever mechanism, as (according to this blogger) it is the most fragile section of the pen. It's also probably better not to grip the threads, as the material is thinner here.
- Heat until your fingers hurt, and back off until they don't.
- Pull the section away from the barrel with a firm, but gentle, motion. You will want to tease it a bit: pull, see if it gives, pull in a different direction. You may twist it, but do so very delicately.
Finally, two notes on removing the dessicated sac:
- There isn't much room to maneuver as it's such a small pen, and as such it will not be forgiving of messing around with the wrong tools. If it won't come out, try some compressed air from a can and if that doesn't work find a long, and very thin, metal tool.
- It is important not to crack the nipple that joins the section to the sac, as the nipple on the Peter Pan is thinner than usual. I would suggest using nothing harsher than a fingernail, going slowly, and to soak the part gently in cold water if needed.