Sweet find! So it looks like it’s from an Ampex Quad Video Head and the part is called a quad rotary head. And they’re really expensive. It definitely seems like this will need to be 3D printed.
This is an Ampex 2-inch video quad head. Comes with a depth gauge used to measure tip projection. Also included are a couple of quad rotary heads and one other head from a helical video tape recorder,
www.worthpoint.com
Though that isn’t the compete greeblie, there is a base to it as well. So there’s still another half.
Edit: the bottom half appears to just be what it sits on in the machine. Here’s a video showing more information about the machine (or a similar one)...