Apologies if my question has already been answered. I did a search and didn't find what I want to know. I have the Sheaffer pictured (I hope) below. I've used it a couple times without problems, but now the filler mechanism has become almost impossible to move. I looked up a couple videos on servicing touchdowns, but none were quite like the one I have with the window. The barrel of others in the videos seemed to unscrew from the feed section easily; mine won't budge and before I try to persuade it further, I thought I'd ask here if anyone knows whether the section and barrel are supposed to come apart on these models. If not, do I merely need to lubricate the metal tube of the mechanism to get it to move again? What questions should I be asking? Thanks in advance for any advice anyone has to offer. Ruth