These wretched little hollow stamped steel devices are normally only found in bronze finish, for KVK2Xs. But here we see bronze (Hindenburg Cross), Silver (a Principlality of Hohenzollern house order's Silver Medal X from WW1) and Gold (Austrian WW1 Commemorative medal).
These were stamped in one piece with impractical, too small "nubs" on top and bottom where the sword blades join. That speeded up production, since two bent prongs no longer needed to be carefully soldered at that point. Unfortunately, the nubs are too short to fit through the holes stamped in the center of each Third Reich era ribbon bar backplate, so it was right back to 1915/16 again, and folding the pronglets behind the ribbon and then sewing the ribbon down on TOP of the backing.
That is why so many of these are missing on 1942+ ribbon bars.
The immediate identifier is that the triangular spaces between the upper crossguard of each hilt is no longer cut out under the sword blade above.
It is very unusual to find these other than bronze finished. Usually they were mounted "mix and match," with silver and gold from earlier stock (prongs and cut out solid devices) and only the hollow stamped uncut bronzes. Exact introduction period is unknown, but I have never seen them on pre "East Medal" ribbon period ribbon bars-- so no earlier than 1942.