I think it's around 1840 - the way the foot is cut with the separate sections is similar to many from that era as is the way the base is cut and the overall shape of the goblet with the waisted cut. Although I've only seen one with the same arched outline and that was under a Neuwelt attribution as far as I could see.
I have seen this type of decoration before but as is the way, I can't find a comparison for the enamelling at the moment. There are thousands to sift through in becher form - however if I spot one on my travels I'll come back to the thread and post.
I've been through the Neuwelt book and Das Bohmische Glas Band II but couldn't spot anything with similar enamelling unfortunately.
It's quite hard to see the enamelling but it looks on the photographs as though it is silver overlaid onto an enamel underlay decoration and that the silver may have worn off in places? It's difficult to tell with the photos unfortunately. Also silver does turn darker when it oxidises so that might be the effect your seeing perhaps?