Recently acquired a 1957 vintage Pilot Super 150, switch converter, with a great 14k flexie nib. Nib is perfect, converter is like new. The ink does not flow properly. I removed the nib and cleaned the channel on the feed; soaked overnight in Windex; removed the switch converter; forced water through the section and nib - plenty of water flows easily. Still, after a fresh fill of Iroshizuku, only about one line and then dry as a bone. Oddly enough, the pen will write with the nib inverted - upside down. I've written to Pilot, no answer yet. I don't know how to remove the feed, which probably is just gummed up. After all, it is 60 years old. If I am unable to clean the feed and section? Where then can I find a replacement section and/or feed?