The under hood black I am not sure about. The back hood hinge bolts are correct color but the front on both sides are black. As far as the springs, Both of my cars have painted springs and are original. My trunk lid mounting bolts are painted body color also on both cars. Not sure if there was a difference for 63? The 63 I got out of Iowa was original black under hood paint and the front bolts and cowl tag were not painted like you are saying. I plan to go and look the car over really good. I thought there was going to be a 62 (Brice’s old car) there this year but maybe he is taking it to another auction?
There was a service bulletin for the 63 f-85 front fenders to add sealer to the seam of the inner fender and the fender because water was entering the engine compartment through this seam. I doubt that is why the front bolts are black though.