Good observations!!! It also has a 4 spoke steering wheel, and hand brake located on the adjacent to the transmission tunnel. These and other characteristics suggest a prewar 170V.
I am a little confused by the engine block and transmission. The engine block is missing the mb star cast into the right left side, and I don't know what the extra cylindrical tapped lugs are for located just below the radiator inlet tapping. The transmission gear box cover has ZF cast into the top. While I believe the MB transmissions were made by ZF, I never have seen their name identified in any way. Is this typical of the prewar cars?