All we need here is the vehicle manufacturer, model and year of manufacture.
Up to the Experts.
Mercedes-Benz, c. 1926?
Not Mercedes-Benz and not 1926.
Horch?
No
Benz?
No
Is it German?
Yes.
Hansa-Lloyd?
No.
Audi?
No.
Brennabor 1.5 ton six cylinder truck, 1928?
Brennabor is correct, but the puzzle truck is a bit older and has a lower payload.
Typ R 33 half ton?
1925 P23 one-ton?
That's the correct truck but the wrong year. Locked
1926?
See #3 :headache:
1927?
Yes, it is a Brennabor P 23 8/32 PS from 1927. In 1929, the puzzle-truck advertised the racing successes of Brennabor racing bicycle.