Gary,
My opinion is that it was used through the prototype* development of the SA daggers.
The reason I hold that opinion is that I am aware of three blades with this mark and have seen a photo of a fourth.
The first of the regular production Eickhorn SA daggers had the large oval trademark and these were 1934 vintage.
This same mark is seen on the Fire leader's dagger.
Dave
*They are called "Christmas Daggers" because they were given out before Christmas of 1933 to senior SA men. This is what I have read and is based on news reports in Solingen trade papers at the time. I have not read those original papers so I could be entirely wrong.
