So there we are... apparently a kind of racing plane, definitely not german (I should know otherwise
), but built around a german engine.
The engine clearly looks like a 601, not a 605, so this is not a post-war design (in that case any engineer would rather pick the higher performing 605 as it has the same dimensions like the 601 more or less).
According to what we know nowadays, the design must have been an epic fail.
The radiators on the fuselage side make smooth airflow around the tail section an impossible thing, thus the achieved speed will be way below the aimed target speed and most probably issues with tail flutter would occur surprisingly early.
Who would do such a mistake?
From the components used, it could be some eastern european country, Italy or Japan.
The inner main gear door covers and the tail gear remind me of a Ki-61, this would also match the strange radiator desing that might have been influenced by a sneak peek across the pacific ocean (P-38 anyone?), so this time I put my money on the "Japs" pile again.
Best regards - Mike