One is clamped together w/pinches, the other is with a band/clamp.

Any idea?

band clamp style:
http://imageshack.us/a/img541/3513/lp34.jpg


pinch style:
http://imageshack.us/a/img809/7973/8xs1.jpg


The shiny clamp style is an NOS one with the label on the box for 1971 e/b-body:
http://imageshack.us/a/img32/4708/jwmn.jpg