The top one, i'm not sure what that is. It's hard to get any kind of scale as to how large or small it is.
Try laying a ruler beside the item so we can see approximately how big it is.
The 8mm Geco case is very likely a blank.
Geco is a trade name used by Dynamit Nobel, a German manufacturer and apparently the parent company of Gustav Genschow & Co.
The 8mm blank was a fairly popular cartridge for blank firing guns in Europe when those were still allowed.
As you can see from this page (
http://www.google.com/search?q=8mm+b...aq=f&aqi=&aql=) there's still a lot of interest in them.
One use for them that just popped into my mind is for training retriever dogs for bird hunting. The blanks get the dogs used to the sound of gunfire. It's possible you found one that was so used.