Thread update.
The elbow in question was likely an early 914 6 feature.
I was just going through parts and discovered there were two versions of the oil filler
neck.
This second version eliminates the seperate elbow by aiming its breather nipple
toward its destination. The breather hose is now a single long piece.
The short hose, 90degree tube and two clamps are eliminated.
As a bonus, the hose no longer gets rubbed on by the rear lid torsion bar roller.