sorry no pics

1970 + up to mid 1971 had hard seat backs, with metal hinge covers + the long seat release button was incorporated in the metal hinge side covers.
the side covers were painted to match the seat color, but the buttons were black
the seat backs are interchangeable from left to right

late 71 and all 1972 seats had hard backs, + a short chrome seat release button, + the seat backs are left+ right specific

73-4 didnt have hard seatback,
just all vinyl covered