Fluted
(50-53?)

Outside
of lense

Symmetrical pattern.
Has wide brow on side with Bosch emblem.
Opposite side has "LE 1801 B" Then a "NL" inside a circle, then an "A" in a circle followed by "1209"

Inside
of lense

Nothing is written on inside

Outside
of lense

Symmetrical pattern.
Only has VW symbol. Appear to be beetle lenses.

Inside
of lense

Nothing is written inside

Fluted 
(62-67?)

Outside
of lense

"Pie" pattern.
Has VW logo near bottom.
Almost in the center of  lense is an "E1" inside a circle.
"4441" is written below the circle

Inside
of lense

Fluted

Outside
of lense

"Checkerboard" pattern.
Outside has "E1" in a circle with "4450" written below it, followed by the HELLA sign.
Written along bottom edge is:
1-74 617 rechts -  Made in Germany  IGM 1242LA

Inside
of lense

Nothing is written inside.

Non-Fluted
(possibly 1955 only)

Outside
of lense

These came on my Jan 55 Canadian delivered barndoor. I was told these were the infamous 55 only buckets. Notice the arrow that is stamped into the ring that matches the arrow molded into the glass. Check out those very long retainer clips too.

Top of lense has OBEN and HELLA.
Bottom of lense has E1.067.01 and below that a slightly odd looking VW symbol, followed by 'Made in Germany' with an arrow pointing down at the arrow stamped in the ring.

Inside
of lense

nothing is written on inside