It took me a few days but I finally found and uploaded a photo that shows the THREE variations of the 1993 USMC Trials bayonets.
The top bayonet is the model with the riveted tang. The end of the blade tang extends through the pommel and is peened over, securing the pommel in place. This unit cannot be disassembled. Chris Johnson posted a nice photo of a riveted pommel bayonet that had not been peened where you can see the component parts:
The middle bayonet is the type that sold on ebay 28 OCT 08 for $2150. This bayonet has a solid tang that is drilled longitudinally and threaded. The pommel is held in place by a socket head cap screw that screws into the blade tang. If you look at the photograph you can see where the threads cut through the sidewall of the tang. This results in a very weak section at the end of the tang. I know of more than one of these where the back end of the tang has broken completely off.
The bottom variation is what I call the "short tang rod". It has the solid tang turned down and threaded about half way down the length of the hilt. A short internally threaded sleeve is then fastened to the tang and a socket head cap screw fastens into this threaded sleeve to retain the pommel. This variation was NOT submitted to the USMC but was made in small numbers to test the feasibility of the design.
According to Buck they made a total of 350 of these Trials bayonets. 175 where the riveted pommel and 175 had the drilled and threaded tang. Only a handful of the third variation were made.
Threaded Mode