Checked the instructions for Miniart 35124 GAZ-AA:
The rearmost cross-member of the frame is part Ba22 and it has the opening for the tow hitch and the mounting plate. i.e. everything except the actual hook in Frenchys image above.
Part Ba11 is the spring on the inside of the frame.
The actual hooks are provided as two options:
1. The version shown in Frenchys image, part A56 is the U-shaped fixed part with A81 + A80 providing the "pin"
2. Part A82 is similar to US/NATO tow hooks
Had to dig through the stash to find the proper box
/ Robin