Getting close to a source for f85r2

[ReneZ]

Since Laufenberg's Regimen was written in 1429, this gives a very valuable provenance indication for the Voynich manuscript. It also suggests that the date of creation (at least for the f85r2 diagram) is close to the later dates in the Carbon-dating range (1404-1438 with 95% probability).

The "Handschriftencensus" already linked by @Bernd is the best resource I know for finding manuscripts in any (?) German dialect.
It gives You are not allowed to view links. Register or Login to view. of works for Laufenberg..
   

and You are not allowed to view links. Register or Login to view. of copies the the "Regimen".
   

It is worth going through both lists. 
The tantalising "Buch der Figuren" exists only in one copy, that is: existed, as it was burned in a fire of the municipal library (You are not allowed to view links. Register or Login to view.):

On 24 August, the Museum of Fine Arts was destroyed by fire, as was the Municipal Library housed in the Gothic former Dominican Chruch, with its unique collection of medieval manuscripts, rare Renaissance books and ancient Roman artifacts.

The earliest known copy of Regimen is indeed from 1429. As this is quite close to the end of the date range for the Voynich MS, both from the C-14 point of view and the clothing style, I see two possibilities.

1. It is indeed a copy of something close to the origin, and this then also puts a constraint on the location of the origin of the Voynich MS, or its author, as he//she must be from roughly the same area.

2. There may be other earlier sources. Certainly, for the text there were sources used by Laufenberg, but these may not necessarily be too relevant.