Camillus M3 knife - real or reproduction?

Now someone will identify it for you...nice enough blade too.

Yours is "blade marked" rather than "guard marked" so it was made a bit earlier, and potentially worth more. Looks good to me! - Bob

Thank you for the replies and information. Before seeing this thread I didn't realize the the history of the M3 knife. I received it from a Marine friend from the WWII and Korean eras and cherished it as a gift.
Doing some searching I did find a very useful article that is quite easy to read. One of the most interesting bits was there just over 2.5 million made by 9 different manufacturers.

M3 Trench Knife - The Fighting Knife - Antique Outings

Here's an excerpt concerning the marking I had asked about and confirms the the information the experts here provided.

"During the short time the M3 Trench Knife was made (1943-1945), there were 3 distinct patterns. The first and early pattern had “US M3”, the manufacturer name, and the date 1943 printed on the blade. The second pattern was similar to the first, but it omitted the date. The third pattern, which occurred sometime in 1944 removed the markings from the blade and placed them on the underside of the crossguard."

Thanks again

I think the repro's only had 1 pin holding the butt on.