I have seen at least two of these previously.
They were called "German Made Texas Bowie Knives" or something like that. There was a thread about them too if I am not mistaken.
Could be some post war parts that were converted, but most likely a modern variation on the old RAD EM dagger. The blades looks new - that is for sure. So is the etching of course, as is the scabbard and frog.