M9 plaque on Eb'Hell...
 

http://cgi.ebay.com/US-M9-Bayonet-Mo...c#ht_506wt_901

...You are looking at a US M9 Bayonet Mounted on DESERT STORM Plaque. Mounted to a faux but metal M16 type barrel (this is not a real gun part, only a replica made for the plaque, just for looks)...

I saw this auction yesterday as well.
The example I have in my collection has the square front sight in metal, but the "fake" rifle barrel is made in plastic.
More information about this bayonet with an interesting picture I posted of the original advertisement at the following link
http://www.quarterbore.net/forums/showthread.php?t=2212
Also some of you might be interested to know that the bayonet was originally supplied with the following sticker on the blade
http://img121.imageshack.us/img121/4638/img1931rp.jpg

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