The Mitsubishi Ki-51 (Army designation 'Type 99 Assault Plane'; Allied reporting name 'Sonia') was a light bomber/dive bomber in service with the Imperial Japanese during WWII. Several left behind at the of the war were pressed into service by the Indonesians against the Dutch and known as the 'Guntei'. This one was abandoned at Babo airfield in Indonesia's West Papua province where it remained until the 1980s. Recovered and restored to static condition, it was painted to represent a surrendered Japanese aircraft used during the Indonesian National Revolution between 1945 and 1949

One of the Japanese types, that were used in the early stages of Indonesian independence.

As far as I know, this is the only surviving Ki-51, or Japanse Army Type 99 Assault Plane, or 'Sonia' to the Allies, or Guntei to the Indonesians. Its wreck was found in New Guinea in 1987, but it's painted as a Ki-51 used by the Indonesians against the Dutch after World War II. Radio mast is broken and pointing forward