Special nickel-plated Nazi presentation PP's exist but are exceptionally rare.
As a general rule, Nazi presentation pistols are like 1970 Chevelle SS 454's- roughly 99% of the examples in the USA today are fake, so a potential buyer should proceed with extreme caution and seek accredited expert advice before paying any sort of a premium for one. (Muscle-car collectors have a joke that there are roughly 10x as many Chevelle SS 454's on the road today than the number that originally rolled off GM assembly lines, the ensuing 40 years of rust and wrecks notwithstanding.
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IMHO it's far more likely that the OP's pistol is a refinished garden-variety Nazi-era commercial-proofed PP rather than some sort of rare presentation piece, even a redone one. Many returning GI's dressed up these pistols in an effort to create a more impressive war trophy.