Just to give you a starting point. 4K is not a realistic figure. You will have atleast 1K in materials if you use quality paints, sealers, etc. Paint work usually goes for 65-75 per hour. Colour sanding and buffing? Rust repair on a e-type is not all cut and replace. You need to start with a fixture. I for one would not send 8 straight days on a metal job...not realistic. Things need to cool, etc. One side at a time. Quality trim will take most if not all of your 3K. You have no buget for brakes, front end/rear bushing, seals, etc. These are expensive to work on. Has the head been converted to hardend seats? A 2+2 has shyte loads of chrome and misc fittings the will need re-choming, etc while they removed for paint.
Just my 2P, and not my first time down this road. Buy a quality vehicle and be done with it.