Hi,
I am still sceptical that Klein would simply drop the "Q" .. and say "Hey Alfred... there is no space for you on the cross... if "WILM" can get 4 letters on a ring, surely "KQO" would have fitted as well?
There is one small fact that maybe could have influenced this... According to Wikipedia, Alfred Quenzer died in 1918... If he had been (and i have no idea if he died of a long cancer or was hit by a bus) out of it for a period, maybe by the time Klein and Quenzer started making high volume crosses in mid-late 1917.. old Klein thought... "hmmmm...I am going to have the firm to mayself..." and started stamping "KO" for "Klein-Oberstein".... then old Quenzers relatives said "Nah.. we will keep our piece of the firm..."
It is just a wild idea tossed into the pot... but KO thrives on wild ideas...