Simple question repeated because I get no answer in 2 best forums and my own research. Prompted by discovery of fine 21j Assmann made for Gruen before 1900 that is roughly 10 size. Marked Gruen & Son which was done before 1900. Not recorded anywhere as a Gruen watch as was thoroughly done for the 1895-1904 18s and 16s fine Assmann made Gruens. I cannot find a 16s Assmann marked also from before 1900.