help identify german medal

[Valter]

I don't have to. I've never had any dealings with the gentleman,but he does have a dubious reputation. Stewy S

Dubious is very politely said, unfortunately.
It is a general consensus these badges were made during WW2, BUT in very limited numbers, and since they were made by troops, there were many different variantions. Hence it's almost impossible to proove originality. In other words, chances to get an original one is almost 0. If you want one as a filler, don't pay more than 10-20 €.

But there's a very interesting story behind this shield - a submarine base Lorient was one of the bases on french Atlantic coast that remained undefeated til the end of the war:

http://www.uboat.net/flotillas/bases/lorient.htm