Siemens positions would be far too large for me. I would sell part of it and put it into the FTSE. I would also increase the monthly savings rate and leave €300/500 for individual purchases rather than the other way around, because €100 a month hardly builds up anything.
@Korrekturensohn Exactly, I would at least halve the two positions and reallocate the money to achieve better risk diversification (your other positions only make up a fraction of this).