No. 102, 104G & 106G Safety
The 10x was priced very closely with its younger siblings - the 12x and 13x. In this catalogue from the late 1930s, we see that all three series existed and were actively sold in the market at the same time. Notice that the 104 and the more modern 124 push-knob filler sold for the same price of 22.50 Reichsmark (RM), while the piston filler 134 sold for just a little more at RM 25. Maybe the piston technology and ink window warranted a higher price. Also, see how the three pens look all but identical in key design elements. Finally, notice how the 104 is much longer than the 124 and 134!
For bibliography, see Resources page -->link
The 10x series pens were introduced in the mid 1930s. I believe the 102, 104, 106, and 108 model pens were intended to replace the No. 20 to No. 40 first series of Meisterstück pens. A catalogue from the early 1930s mentions "Frühere Nr." or "Earlier No." next to each 10x model and then mentions the corresponding No. 20, 25, 30, 35, 40, or 45 pen model it was replacing. The 10x deserves great respect because it introduced key design elements that went on to characterize the 12x and 13x series pens. First, the 10x series introduced us to the bi-colour nib - gold and rhodium plated. Earlier pens had the monochrome all-gold nib. Second, the 10x gave us the distinct flat-top cap design with the single thick cap ring that we love!
The 104 came in three variants - the 'G' which we think might mean 'glatt' or glossy, the 'S' or schraffiert implying a hatched design surface, and the super rare 'E' or Extraklasse which had a rose pattern chasing (see 124 E here -->link). It is the only model in the 10x series that came in the 'E' variant. The 102 and 106 came in only two variants - the 'S' and 'G'. In terms of size, the 106G is visibly thicker or fatter than the 104G, but insignificantly longer as we can see in this picture. The 102G, on the other hand is substantially thinner and shorter than the size 4 and 6 variants.
A beautiful 104G and 106G belonging to Joudenali