First let me say that it is your truck, do with it as you please. With that said, let me give you my opinion. I personally don't care for trucks with the interior the same color as the exterior. Like several have said before me, I would go for a neutral color. I'm not sure what the stock color looked like for your '40, but I actually like the Champegne used in the AD trucks.

-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's