Chas: Very nice convex 1914 EK1. The core is very similar to my 3rd reich era Juncker screwback. However, there do seem to be some slight variations in the numerals in the date and the overall shape of the crown. That could just be a function of two different sets of dies. I have often wondered if some manufacturers of the EK may have purchased iron planchets of the core from shops specializing in iron work, then finished & assembled the cores into the manufacturter's frames.
From the configuration of the hinge and pin on your EK coupled with the attention to detail in finishing the edges of the pin, hinge and hook I get the feeling that your piece is likely pre 1919 manufacture.
Your 3rd Reich screwback with the rayed plate is just super. Those pieces with bright silver surfaces and flat white accents are most impressive.
Reservist1