Hello all! Newbie here. I have a purchased a button fill Wearever in need of repair. The button mechanism is a red jewel (plastic). I have ordered a new pressure bar, cleaned the pen but, the red "button" is sticking when it is pressed down. i have taken it apart and cleaned everything pretty well. I am under the impression that these buttons slide rather easily when depressed and will spring back up when all is assembled. I hate to put everything back together with new parts and have the button stick again. What can I do to allow the button to slide rather than stick? Thank so much for your time!