One has to be carefull to work with the De Ridder collection, as far as I know, a lot or almost all of the "contemporary" series like Bartsch - are copies produced by Neumann - so we don't know what Neumann has changed - one has to look at the originals (hopefully Gallica will do the numerous originals in the BN as well).

As to Becker, the manuscript is in Weimar, one would have to compare the differences of de Ridder with those in Weimar.

A photo set is available a Qunenstedt Fotodienst.

The work by Bartsch is listed in books - see my response to a mail by Steven Smith on that.

But again, we see here the copies of Neumann, so one has to be carefull, the same incidently by the Freiberger Bilderhandschrift of Gallica which is a copy of originals, this time made by Brun and not Neumann.