SixthScaleEdward
Super Freak
Those are two different lightsabers you're comparing: the ANH and ESB. The subtle differences you speak of are accurate to the movie prop differences. And actually, the UU lightsaber is not accurate to the ANH prop. It should not have that red button on the "bottom" of the lightsaber, and the "on/off" switch should be on the other side.
Glad someone pointed it out.