Seen the photos.
That is not a model that Glashutte Original makes. Apart from the deliberate mistake of the french 'Reserve de Marche' on a Saschen German watch, the "Big Date" with 2-window frames is definitely NOT Glashutte Original.
The other Glashutte watch manufacturer next door to GO (Lange & Sohne) do have double framed windows for their Big Date display, ostensibly, derived from the clock display at the Semper Opera house in Dresden; but your watch is also not a Lange & Sohne!
I agree with my friend Marcus. You seem to have a watch made "in tribute" to Glashutte Original.