Wagner Schneider Typewriter

I'm trying to pin down this machine, which is only identified as a Wagner Schneider typewriter from 1888.

It looks like a much more elaborate version of Lee Spear Burridge's 1885 Sun index:

Martin Howard Collection

Could it possibly have anything to do with Franz Xaver Wagner? Some of his patented designs from this period look quite similar (notably #393318), but they employ typewheels.

When I checked with Ernst Martin, I was directed from Wagner & Schneider (of Zürich) in the index to a Kosmopolit of the same year, in a section on typewriters for the blind.

This entry seems to be in the main about the Kovâko, made in St Petersburg, Russia.

Friedrich Müller has no mention of a Wagner Schneider typewriter.

The Martin entry which mentions Wagner Schneider is obviously not for the same Kosmopolit as this one:

Auction Team Breker in Cologne says of this more familiar model: "This is the second German typewriter in history, made by sewing machine manufacturer Guhl & Harbeck, Hamburg."

Breker adds that the first German typewriter was the Hammonia of 1882, also made by Guhl & Harbeck (this example from the Martin Howard Collection):