Actually he only asks about a "lens hood" to fit it, no specific hood, a recommendation for a collapsible rubber hood would fit his needs just as well.
The Nikon Part# for that hood is the HS-9. Its still readily available.
That was the latest MF 50 1.4 hood, but there were others. Pre AI "F" model "Nikkor Auto" 50 1.4 probably used an HS-1. Not that there is any functional difference.