Those are all some really nice model 4's... makes mine look not so nice, but I will post it anyway. I am not sure when this was made but am thinking it's out of the 70's. It has a 6" blade, and I like the way it looks although it's not "pretty" or in unused condition. I have sharpened a very nice edge on this knife, and use it myself. I don't have a sheath for it which makes it hard to carry unless I'm taking a pack along... a little dangerous for the pocket.
~dale