Loetz Metallin, Melusin or ?

Here's a very interesting Loetz vase.  I believe it's a Metallin piece, but I'm not positive.  Could it be Loetz Melusin, or another variant? I've seen Metallin pieces in emerald green (the most common) and blue (don't see a lot of blue ones), but this is the first one I've seen in a deep pearl olive grey, and definitely the first one I've seen marked. 

It's much nicer looking in person, as I had a difficult time photographing it due to it's deep color, and reflectiveness.

The vase has an internal molded ten rib optic pattern on the initial layer of glass,  which was then cased in clear like other Loetz Metallin work.   Possibly designed by Eduard Prochaska who applied his gold and enamel painted decoration from 1907 - 1908 primarily.

Equally difficult to read in person, but it's etched as follows:


applied for

made in Austria"

The only other pieces of Loetz I've seen marked with a Patent reference are the Loetz Octopus pieces that are typically marked "Patent 9159"   I'm not positive what country this patent is registered in, presumably it's from the German Reich.