Hi Juan,
If you plan to paint your T-40 body, you should remove all the parts (neck, pickguard, bridge, ...) and sand it. Try with a big grain first (80) using a sanding block for flat areas, then use smoother ones (120, 180, 240).
If the scratches are too big, you can fill them with a kind of wood paste (sorry, I don't know how to say it in English), but don't forget to sand ... again and again. Remember the sanding job is very important. If you can notice some scratches before the painting job, the paint won't fill the scratches enough and it will look like sh*t.
Once done, you can try to ask your local auto repair shop and ask if they can paint your body. Don't forget to use a primer before the colored paint. I'm sure they can paint your body for cheap when they have to paint a car parts.