Hey Sabine - I thought I'd mention that your 28 has features different than we usually see in a 28 because I'm reasonably sure it's a VS3 - or the very early version of the 28.
The cast inspection plate and the unadorned face plate tip me off to this as well as the serial number allocation date.
My 1889 VS2 shares those features with your machine. My 28K which is a handcrank as well has the pear shaped chromed inspection plate on the back and the grapevines on the faceplate. My 1912 28 has the same decal as yours.