Upload & Sell: On
There is only one version of the 50 f/2 H-C and it is called a pre-AI lens. It looks like this...
There were 188,800 of them made. There are other 50 f/2 lenses made though all had the same optical design.
The modification required is to the aperture ring. Here is a link to photos that show the differences between pre-AI and later versions of manual focus lenses which are designated AI and the AI-s. Pre-AI is an alphabet soup of labels.
Nikon made AI conversion kits for pre-AI lenses but these are no longer in production. There are a few of the kits still floating around, so it is possible to make the conversion using a kit, if you're able to find one. Without the kit, it is still possible to make a conversion, but as you note, for the camera you're using it is not necessary to do so. Nikon cameras without a lens focusing motor will accept these lenses without a problem. Cameras with a focusing motor are best not used. Here is a link to a description from Thom Hogan of which lenses work with which cameras.
This is not an expensive nor much sought after lens because of its smaller aperture. That is one reason they can be bought so cheaply, even later versions that include the AI design. As I noted on the Shooting with Tubes thread in the Macro forum, I bought a pristine copy of the 50 f/2 H-C with the Nikon AI conversion kit for $56. AI versions of the lens cost under a hundred dollars. This is not a lens that calls for a great investment simply to mount it on a later camera. I'm very happy with older lenses that have scalloped focusing rings, but I'm only interested in such lenses that have the Nikon AI conversion kit. I have no interest in butchering aperture rings on these old lenses. That feels like crashing a 1957 Chevy BelAire simply to have an authentic crash in a period movie. These beauties of yesteryear will not be replaced. They are best appreciated in their original form. But that's me...