The background of these coins is the transition from so called "Altdeutschland" (German states prior formation of the German empire in 1871) and the the imperial coinage. It is the transition from predecimal to decimal currency system. Before 1871 people in Germany had a complicated exchange system of various state currencies. The common background was the silver standard shared by almost all German states. Germany switched from silver standard to gold standard in 1873. I wrote & published an article about this time periode. It is written in German. In case anyone is interested and able to understand the text, fell free to contact me for pdf.
These coins are well sought after in high grade. Usually they can be found in poor condition. German states and German empire are classical collectors fields for advanced coin collectors. The prices dropped during the past years, you can purchase these for a fraction compared to British counterparts of that age and condition. Now it is a good time to make bargains, but the market will be empty soon I guess...