The Secret of Nikola Tesla
Tajna Nikole Tesle (original)
Starring Petar Božović, Strother Martin, Orson Welles, Dennis Patrick, Oja Kodar, Boris Buzančić, Charles Millot, Ana Karić, Edo Peročević, Igor Galo
It's a drama and history movie, and has a rating of 7.2 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Belgium.