German Novelty Eye Clocks from the 1920's

I'm definitely intrigued by old novelty items so when I was poking around on the internet this weekend I came across the Skull clock pictured in the first photo and it immediately grabbed my attention.  According to a post I read HERE, these novelty clocks were manufactured in German during the 1920's - 1950's with the earlier versions being made out of wood with the later versions being manufactured out of a composite type material.  It appears the most common makers were J. Oswald and Sinn, both of Germany and there were many different sizes and styles made throughout the years.  Apparently the right eye gives the HOUR and the left eye gives the Minutes in increments of five.  Definitely not motorcycle related but the craftsmanship is very cool nonetheless!!!