Adam, please don´t be too disappointed...
I checked in Helmut Ricke ´New glass in Germany´ and the info I gave is from that book.
Signatures on Eisch glass are quite different: handwritten, etched and sand-blasted.
Some pieces from the Pfauenauge (peacock-feather) range e.g. are signed, some are not.
Those factory pieces with a more individuell character like your vase seem to have a
handwritten signature usually.
None of these pieces is (exactly) like the other, so you still have an unique Eisch piece.
And they are lovely!