Antique Kuehl Co. Swivel Clock

This old clock belonged to my grandfather. It is roughly 3 inches tall and appears to be made of brass. The face says "KC Co Germany" under the 6. From what I have found, that stands for Kuehl Clock Company. The back has a wind handle like on a music box, a wind knob labeled "H", and a crescent shaped hole labeled "F" and "S" on each end. The bottom of the stand is a mirror. I have no idea where he got it, could it be Naval or military issued? How old?