I have been offered this M3 fighting knife. It is guard marked, making it a third series M3. All looks right to me but this would be my first U.S. blade purchase and do not want to spend to much. From the research ive done through previous M3 threads these seem to be more desirable knives, especially the early ones with the leather M6 sheath. This is one of the later M3's but still a cool knife. Any opinions would be appreciated!