Stripping paint can be done in a number of ways. The early paint was lead based and later enamel, both are hard to remove using a standard stripper. Best I have used in aircraft paint stripper but it is highly acidic and will burn your skin. Next is caustic soda, again will burn but used with caution is better than stripper. To use caustic soda, you will need a container, slightly larger than the model. I use the bottom of a plastic drink jar, but make sure it is thick enough not to melt with boiling water. Place the model in the container, poor on hot water and add a teaspoon of caustic soda, stand back as it will react with the paint and preferably do this outside. Leave it for a few minutes or until it has stopped fizzing, douse with plenty of cold water to get rid of the caustic soda and clean the model with wire (steel) wool. You may need to redo this is if there is a lot of paint left, otherwise use a dental pick to remove the rest. Continue with a rotary tool to get the remainder clean.
Chassis cleaning may present more of a problem if it is badly pitted with rust. You can try soaking in vinegar overnight and then cleaning with a wire brush.
RULE 1, Read this first. DO NOT TRY TO BEND THE METAL - IT WILL BREAK. There are two methods to consider. Gently tapping the bend with a light hammer/punch against something solid. Warming the model and then gently bending.
If it does break or if there is a piece missing, use a metal based epoxy supported by a smalll piece of aluminum foil. When set be foil can be peeled away. To get the correct profile, more epoxy can be applied. The same epoxy can be used for any pits in the surface, finishing with a fine wet and dry paper.