6S1757 also has original leafs like Brant's photo in reply #4, one having stripes, the other daubs. Although certainly rare and NOT typical, it was seen that late in production (late March SJ).
There was a discussion about the white coil spring stripes on forum 1.0. Most springs did not have the white stripes, only red or reddish brown. IIRC the white stripes were some sort of specification variation identifier, something like a little stiffer, or softer than the norm.