OK, if you would really like the lowdown on the badge, have a read of this set of dedicated pages on the Wehrmacht Awards website. The links on the left will teach you more than you probably would ever like to know about it! There should be a maker's mark that you can tally with the manufacturer's table in the top link.
http://www.wehrmacht-awards.com/german_cross/german_cross_main.htm
You could always post images in the forum. The people there are very helpful despite the seemingly scary nature of the topic.
German military awards are absolutlely riddled with counterfeits - faking them is major industry, and some are really very good. The fact that it was found in a well absolutely confirms it's authenticity.