It depends if there is any pitting under the paint and how much, but there might not be any in which case it would be more straight forward.
The fork crown would be the more time consuming part because it is quite intricate.
Best thing would be, as somebody suggested, to build it as it is and see how it feels.
You can always get a quote from a plating place for both, the whole work done and just the plating and see whether if it is worth the time and effort.
You could check chrome plating prices on Argos and Mercian website for comparison.