Saab 91 Safir RESTORATION PROJECT

[Tomas ACO]

Good day.
I apologize if my question is outside the topics of this forum... I would like to ask for help by this way with the project of restoring the Saab 91C Safir aircraft.
The situation is this: Me and my colleagues would like to bring to life an old Safir that has hung under the hangar ceiling for years, somewhere in Germany. The aircraft is now in our hangar in the Czech Republic at Pilsen-Líně Airport (LKLN). There is no document for the aircraft! The only thing we have is a complete aircraft airframe in its original but very good condition!!! an incomplete engine which we unfortunately assume will be replaced by another more available type...
We are a group of experienced aircraft engineers, ready to spend a lot of money and time. For this project, the physical repair/restoration of the aircraft and its airworthiness is not the biggest problem, I see the "legislation" as the biggest problem. There is the question of the supervision of an aviation authority in which country to register the aircraft, in which category and so on? ...And with regard to the country where the aircraft will fly (Czech Republic).
I will be very grateful for any advice on where to start, for any contact the person who performs the official supervision of this type of aircraft or advice on where to register the aircraft ... I am adding a few pics... Thank You for answer

Tomas