I've only seen writing that says "Made in Germany."  Are there any Sigs new or old that actually read "Gemacht in DE/BRD/DDR?"

I doubt it, as the "Made In" requirement is largely if not solely a US one.

There are some labeled with "DE" as it follows guidlines of a U.N. policy adopted a few years ago regarding manufacture origin of firearms to better track illegal trafficing.  "Gemact" or "Made In" apparently is only "required" in English format in America.  It's why we also seem to "have to go to the hospital" for instance rather than "go to hospital".  American has become more laborious than it's root languages rather than become more streamline and efficient like most others.