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
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