Can anyone put a date to these DK stems please

[mark 2]

I've looked everywhere for info and can't find bugger all but I bet one of you will know, just want to know if the era will pair up correctly to to an 84 bmxycle. And anyone know anything about the mini one too? Not got DK stamped on it but same curved top style and build as the other one but the bottom half is like the square edged ones from 81. Thank you