Nova 64 was a legal and licensed Yugoslavian clone of British Oric Atmos computer.
The board uses a less popular 7905 negative voltage regulator. It can’t be directly replaced with 7805 used in most of vintage computers.
Oric’s keyboard is a pretty poor construction. The cable breaks at the connection to the keyboard board. It can be replaced with a modern HDD ribbon, using every second wire. Another problem are the soldering joints of the key switches to the board – they break very easily and stop conducting, as the holes in the board are unusually large. All switches need to be re-soldered.