I have not seen the actual wording of the 1957 statutes, but my understanding was that they only applied to 3rd Reich awards. There may have been a clause that allowed for the wearing of Imperial period awards, but as they did not have swastikas there would have been no design change, and no particular need to manufacture new ones. In other words, a "1957 version" of an Imperial award is nothing more or less than a modern copy.
"Gentlemen! You can't fight in here, this is the War Room!" - President Merkin Muffley