LEGO Set - Technic - 8837 8074 8830

Set of 3 Lego Technic sets from the 1990s, specifically 1990, 1991, and 1992. Two of the sets are apparently complete: the 8837 and the 8074, both with their original instructions. The pneumatic system of the 8837 doesn't work, but maybe it's just a matter of adjusting the assembly, particularly the small air delivery tubes, or not. Some spare parts are of a different color compared to the box photos, but they remain identical in shape.
The operating system of the accessories for the 8074 is functional, with additional parts because there are multiple assemblies, I imagine, for each set. (Note: I only performed one assembly example, which is the one in the photos.)
The 8830 Lui set is not complete; it is missing some pieces and accessories, as well as the assembly instructions.
The boxes are in good condition, especially the 8837, with no tears or marks. The 8830 has slightly more wear, and the 8074 is the most damaged, with some tears noted.
The plastic display cases are present and well intact.
The parts will be disassembled for shipping.
I tried to be as realistic as possible in the description and photos to inform you as accurately as possible.