As most of you may already know, I purchased at a local pawn shop, a copy of a USMC Ka-Bar. I figured it may not be real, but was curious to see what it was all about. After taking it home and looking online, I was able to quickly figure out that what I had on my hands, was indeed a copy. Now I do love a good copy, and was generally impressed with the build and quality of the knife and sheath. I now needed to get myself a real Ka-Bar to see what differences exist.
Thus, what follows is a very close examination and my thoughts on both knives. Hopefully by the end of this, a copy of the famous knife should be obvious to the less knowledgeable folks regarding this knife.
Now onto the comparison.
Right off the bat, you can tell that the real Ka-Bar has rivets in support of the stitching of the sheath. The copy lacks the rivets which give the sheath much needed support.

The copy copied the shape of the sheath rather well of the original.

The biggest hint that you have a copy, no Ka-Bar stamped into the sheath. Note also the slight lack of detail in the USMC symbol of the copy. Also note the real stamping of the original, showing the two tone colour one gets when stamping real leather. The copy does not feature this. Also note the grain of the leather in the copy. See those holes in the bottom of the stamping. They are still present, telling me this is not stamped on like the original.

Still looking at both sheaths, you can tell the copy, on the right, has a smoother more refined finish on the end. However, the original shows lacks this smooth finished edge...but shows more honesty as you can tell it is real leather. The copy also has a two tone to it...telling me it composite in construction. Mayhaps the top and bottom pieces are vinyl or some other material. I must say, the sheath on the copy looks and feels good...but the details tell otherwise.

In the following photo, we get a closer look at the sheath clasp. Note that the copy is in the background. The snap on the original is of superior construction and looks more refined. Note the difference in pommel pieces in both, and the different groove patterns of the handles.

Taking the knives out of their respective sheaths, big differences are now visible between the copy and the real thing. Note that the real knife has USMC stamped into the blade. The copy lacks this. There are differences in the blade geometry and blood groove shape as well. The hand guard is completely different in the copy...being straight and thicker than the original.

Flipping the knives over, you can also see that "Ka-Bar Olean NY" is stamped on the original. Thankfully the copy does not try to deceive in this aspect.

Taking a closer look at the leather washer handles of both knives, you can clearly see the original is smoother and better constructed. The metal valleys are even and well defined. Not so on the copy.

Here is a closer look at the hand guard of the copy on top, to the original on the bottom.

Looking at the pommel cap, you can tell that the Ka-Bar did a better job in the finishing details. Both knives feature the tang just breeching the pommel end cap. Both also feature a, what I can only guess at, is a pin which holds the tang to the pommel. I originally thought the copy had a set screw here, but upon closer inspection, it looks like similar construction to the Ka-Bar...only not as nice finish wise. Likewise, there is a slight rotational movement evident in the copy. Nothing major, but it is there nonetheless.

The Pearl Harbor Ka-Bar is a nice looking knife with a nice motif on the blade.

Conclusion.
The copy was cheap...but in actuality it is a false economy. The copy does not compare to the Ka-Bar. The sheath of the copy looks good. In fact, it looks better than that of the Ka-Bar, but upon closer inspection, it is made of inferior materials. That concept runs through the copy as well. The leather washers on the copy are not well implemented, the knife blade isn't as sharp...not to mention what steel is found in the copy to begin with? For the extra 20 bucks, go for the real deal and you won't be disappointed in the long run. The copy looks and feels good in the hand, but it does not compare to the knife it was based upon.