Here's some basic help to get you started:
The rotor/shaft needs to go back into the round sheetmetal case that's lined with powerful magnets.
There's a BB at both tips of this shaft--large BB on the stubby end of the shaft that goes into the case.
The ring with the 3 brushes and wires slides into the side of the cast aluminum gear housing.
You will need to fiddle with sliding the long end of the rotor shaft into the housing, thru the brushes, and lift the brushes to fit over the wound rotor as you mate the rotor casing and shaft to the aluminum housing.
Remember that there is a tiny BB at the tip of the shaft that fits into the aluminum housing.
The cutout slots in the rotor casing each allow a square nut to be slipped into the slot to accept the two hold-down screws.
Once this part of the assembly is done, the large gear fits into its spot inside the aluminum housing and meshes with the shaft's worm gear, the rotating park plate(with the segmented brass contacts) sits atop the gear, and the steel cover plate with the copper wipers is added to close the aluminum casing.
I cannot see all your screws, nuts, BBs, and fasteners--you will need to test-fit and sort thru these before assembly.
Some advice: thoroughly clean all your parts carefully and with the proper solvents. Apply non-melting grease to the gear faces and teeth; clean all electrical contacts, check brushes look good, and everything rotates smoothly without wobbling.
Next time, spend some time drawing/photographing everything as you disassemble an item, being careful to watch for unexpected teeny parts like BBs and springs. The more time you spend beforehand documenting your disassembly, will ultimately boost your knowledge and confidence doing the re-assembly.