From what I can see by your picture you have 3 road wheels. If you're missing wheels on the other side that is where they would go. Otherwise, they can be mounted on tank body as extras like a spare tire for a car. Also, the machine gun gets mounted in that 'Y' shaped thing (cradle) and then mounted on top of the turret. Look for a small hole, on top of turret, to mount it in. I see a spare hatch cover but I don't see any missing on the tank so use as a spare. The rest of the stuff would be stowage (backpacks, ammo cans, Jerry cans) and can be glued anywhere on the tank body or keep as extra parts. However, Boilermaker1 is correct in that none of that stuff would have been mounted on the tank during transportation.
I mount everything on my tanks because I like to see them ready to go into action once they are unloaded from the rail cars.
Rick
