I am wondering if anyone has experience fixing this type of warping in a Conway Stewart pen. This one is a Duro 26 model. You can see in the photos that the cap has shrunk around the point where the inner cap begins. I just acquired this pen and the plastic seems quite fragile so I don't want to harm anything. I thought to gently heat it and try to push the warped part out from inside, but I'm not sure if that is the best approach. I am assuming this pen is celluloid, but perhaps it is casein?
This pen is a reversed cracked ice pattern, which seems to be a rare color, and is also pretty large (see comparison image with Conway Stewart 27).
This is my first time asking for repair advice here, but I have received so much help from postings on this forum. I really appreciate any suggestions -- Thanks!