I have an old lujtic mono gun number 637. As it is now it extracts the shell but will not eject it. What is missing to make it eject? Is it in the forearm? Someone told me that it was missing a spring around the extractor. Remember it is an old one. I was told the new ones have a small plate that is located in front of the extractor, and some have some small screws that need removed or installed I don't think this has either. Thanks in advance for any help.