More pictures of the iron cross itself may help determine why this is.
Lately there been a discussion of the L/12 or 13? that the marking should be on the cross itself, not the ring. Could this be an example of a dealer trying to hide this? I know nothing about the iron cross just FYI, don't even have one.
The estate could have bought it from a dealer though... Like I said I know nothing about iron crosses, don't collect these. However, there are many others here who have great knowledge on these. I'd wait for them. The new picture should help them as well, thanks.
The cross is an original '123' - Beck, Hassinger & Co.
This one is marked as such but very poorly. There is no suggestion of the mark being ground off as there are no file marks. It might take some squinting through eyelashes to read the number as '123' but that's what it is.
You will also note the frame has some double stamping lines on the beading, a poor quality cross all over but a good one.
Try a search for this maker and look at the makers mark on the other examples posted.
Looking for LDO marked EK2s and items relating to U-406.....