There were four ebony EB series guitars - two classical, two steel string. Yours is an EBDG, the steel string dreadnaught. They’re only in the 2005 and 2006 catalogues.
I don’t think it was a common occurrence but I don’t think it makes it particularly collectable or valuable either. There are some mislabellings from the Japanese production era that are interesting because they tell us something about how or where the guitars were made. But in this case, somebody just picked up the wrong stamp or picked a brace from the wrong bin.