Airliners.net shows a similar door and paint scheme within an AN12.
Photos: Antonov An-12BP Aircraft Pictures | Airliners.net
The flight deck was the only pressurised area on the AN12 and this would account for the hefty engineering standard of the door. I'm not sure why there would be windows in it, but I suspect that they provide a 'blow-out' feature in the event of cabin overpressure; hence the grilles on the flight deck side of the door.
TCF