Hasbro Robot Missing Chest Plate

 I bought this robot from an op shop for $3. (I gave them back the other toys in the bag).

It is missing a chest plate but that should not be too hard to fix.

For scale comparison that is a 1/32, German WW2, 21st Century soldier sitting in the cavity.

Does anyone know what the robot is meant to represent? It doesn't look like it 'transforms' into a car. Maybe it is based on the story about a huge alien robot and a boy, The metal giant, I think it was called.

Anyhow it does not matter because I am going to use him as a generic large battle robot or possibly, vehicle.

I want ideas for additions and color schemes. Even if I don't use your idea I'd love to hear it.
The general categories tend to be bare metal, bright colors and camo. Of course, something that big is hard to hide which is why, unless they have super dooper armor resistance I can't see something like this catching on. Just the same, it will be fun to convert and paint.