1932 Mercedes Benz diesel Lo 2000:-
https://upload.wikimedia.org/wikiped...32-Lo_2000.jpg
The big one looks to me like a L6500, which was introduced in 1935.
The square (wooden?) cab was replaced by a smoother metal cab in 1938.
https://translate.google.co.uk/trans...00&prev=search
Though the L6500 was only two axle - the L10000 was three axle and produced from 1935 to 1938/9.
There was also a 6x4 L8500 produced from 1932 to 1934 and from 1934 to 1936 (which was derived from the N56 - 1930 to 1932).
The 1934 to 1936 L8500 had a 150HP engine instead of the 120HP of the earlier version.
See:-
Mercedes-Benz vehicles 1926 to 1944.
.