A Rare 1:72 P-40B Aluminum Factory(?) Model from Late 1930s

As my family's legacy, this aluminum model belonged to my grandfather, who joined the Republic of China Air Force in 1936.
This model survived because it has no sign or mark telling its history and was always treated as a toy. It lost both landing gears and propellers by my father, who was born in 1947 and toyed with it in his childhood. We had very little information on the service history of my grandfather, as he remained silent under the communist regime and passed away in 1976.

I guess this is a Curtiss factory model as a gift to my grandfather, a member of the Republic of China Air Force or Flying Tigers (AVG). Could anyone find a sister of this model?