I also have one of those Colt-marked bayonets. I got it from pre-ban arms.com as it was the only bayo I have seen that fits a 16" carbine
It is actualy a very sturdy blade, although on the slim side.
Razor sharp, and holds an edge very well.
Although I like the fact it fits my LE Colt, it is not the bayo/knife/tool the M7 is.
you can see it by cutting /pasting this link ----->
http://prebanarms.com/detail.asp?product_id=a03