Also for Prewar Ives O 135 series passenger cars, how do I get the roofs off?
Many, Many Thanks!
Use a smooth flat tapered plastic tool. Like a small stiff spatula. An automotive plastic trim tool might work too. I use the handle end of a plastic handled medical scalpel.
Start at one corner and gently work your way down under the lip of the roof, along the edge of the car body.
Put a towel down, cuz the roof will "pop" off , sometimes with momentum. You don't want it to land and scratch the paint.
To put it back on, start one side and gently work it back on. You will most certainly lose a few tiny chips of paint when putting it back on. Not really any way to avoid this, but they are usually under the lip and cannot be seen when the car is together.