I have a saxophone that my father had as a child and I later dabbled on while playing the oboe. The sax has etching on it and says American Knight. It says made in czech, and has the patent number 64402. I do not have the mouth piece and the brass is tarnished. The lever for the top register is slightly bent but I can fix it. I am trying to find out it's value to see if it should be insured or not. Any info you can provide would be most appreciated. thank you in advance.