Do not restore this
Simply soaking it in the correct solution will clean away the rust...
i would suggest removing the grips first gently and I would not suggest rubbing on the finish with wd40...
Less you mess with the finish the better it will look in the end
Listening to Hondo44 would be my best recommendation
Pitting will still be pitting but gun should clean up well
Very nice old gun you found
God Bless and thank you for sharing it with us
John

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