1963 Mercury Monterey Originality
 

My 1963 is currently 100% original. I am currently finishing up an engine overhaul and am considering upgrading the stock non-power brakes and steering to power...adding in the vacuum assist boost and a rebuilt power steering from a 1962 Mercury. I am also thinking about the installation of the T10 4-speed long-tail shaft tranny made for this vintage car.

How will these improvements degrade the overall value?