6 kreuzer 1800 S - Error - "A" overstruck on "C" ?

Maybe I'm wrong but it looks like "A" in word "KAI" is overstruck on "C" or "O". Is it possible on this kind of coin ?

This is very interesting. What most probably happened is that the engraver "anticipated" the following word, which also starts with a "K". He soon enough realized his mistake and fixed it (before having engraved the umlaut on the "O"). This kind of mistake happened all the time in manuscript copying.