Well I guess I can comment on this:

I don't particularly care for the way that the '33-'34 is done and agree with your painter's reasoning.

Is there a way that he could fill in the outlines he made with a water based paint - something like poster paint that kids use that can be washed off. IMO, there is almost too much area of your sweet car covered for a small roadster and that the tape outlines really dont give you a good enough perspective of that.

Why is he considering painting over the louvers as if they didn't exist - they do exist and they, IMHO will show up like a sore thumb with interrupting black lines in your hood sides. Why not change over to solid hood sides if that's the way you are going to go - if it's a Rootlieb hood, the solid side panels are (or were last fall) $200/pair.

Whatever you do I'm sure it will look great