The pics aren't the best, can you post any more? Straight on front and back please - and the right way up!
Saying that though, I think the second one posted stands a chance, I can't see too much that makes me think fake but better pics would confirm. I have no idea about the first cross and can't find any originals to compare it with.
Looking for LDO marked EK2s and items relating to U-406.....