All those 70thies suits from Rundschau are unbelievable well tailored in German standard. The Rundschau's of the 70thies are precious.
And don't think those people showing their coats cannot cut a pair of trousers...
I don't know about "standards" in tailoring, but many tailors in Germany were and some still are from foreign countries.
There were a lot of Italian tailors working in Germany back in those days, so part of the credits for fine workmanship (should) go to them. Plus I guess that not all the suits kicked out by German tailoring firms were "impeccable" (just like in any other country, even in Italy and UK)!
What's on display in Rundschau magazines is for show only and there is the rule that the master tailor should look his best, at least in public.