[RolandF]

Concerning this "thin white band" - this is not a marking at all, but the position, where the joint between tail unit and fuselage is covered by tape and painted over with camouflage.
Tail unit and fuselage were delivered and produced for messerschmit by different subcontractors - oftenly by unskilled personnel - so the fit of the parts was rather bad and caused gaps which had to be closed.
Same goes for the joint between fuselage and nose unit.
If this tape is torn off by an accident or by excessive wear the unpainted or primer-painted surfaces appear which seem to form a thin tailband.
That´s the way how "Yellow 3" from 3./JG 7 shot down by AAA "received" its ominous tailband or III.Gruppe bar...

Regards

Roland