That looks exactly like those brochures of German aircraft of that era, you can find other examples
in the old LuftfahrtInternational issues. And there, too, you can find the typical style with charts, tables
and data in the middle and the last pages used for general arrangement drawings artist impressions.
In this case, it would be interesting to know (and see) any kind of 3-view, as it would allow for easier
clarification, if it we really are talking about the Fw 62.
As in the case of the "Baubeschreibung Bord-Erkunder-Entwurf 82075", this one about the Fw 191 is an
original document, published by Focke -Wulf during the '30s/'40s. Cannot tell exactly in the moment, where's
this company got to, probably due to several mergers, today its remnants are part of EADS. Sso maybe that
COULD be regarded as the source. But if this "Baubeschreibungen" aren't present in their original form (via
eBay, for example), they probably come from some sort of publication. I already mentioned, the LuftfahrtInternational
magazine, which often published such material, the newer Luftfahrt Archiv somehow is following in these steps
today and there are lots of other publications, which are printing that material again. And of course, there are
several websites doing so. And that's, what is needed as source citation !