I now have my Elna up and running, what a great little machine so far. I tried last night to set up the case as pictured but ran into a snag. I was wondering if anyone else had this come up and how they solved it? When setting up the case the little metal prong that is supposed to fit tightly into the rubber/plastic piece on the opposite side will not go in. It will not close for a nice smooth top. If it was originally a semi hard rubber piece it is now hard as a rock. Was there another piece on it that is now missing? Photos added. Thanks for any help in advance.