Years ago I had seen a copy of Nazi helmet decal application specifications, (centered on vent hole, top edge of decal so many mm from bottom edge of vent, etc). In a perfect Nazi world I believe that every decal application would have been dead on perfect--where they wanted it. That was their specifications. The fact that we see many decals off center can only be due to human error IMO.
Imagine that you are a decal applicator(ess) doing the same monotonous, boring job month after month. Perhaps your mind is wandering and thinking about the war and what might happen to you and your family if it is lost.
Perhaps many of these SS decals are tilted to one side because in the applicators mind he/she was placing the SS runes perpendicular (to bottom edge of helmet)instead of to the edge of the decal by mistake. This would certainly not be outside of the norm for a boring, repeditive, monotonous job like helmet decal applicator. Such tasks can cause the mind to do strange things.
I certainly do not believe that it was purposely done that way.
See Goodapple Vol.I pp.59-61 for other examples.
