There's a whole lot more than just Fords and Ford stuff at the Henry Ford/Greenfield Village, automotive stuff is just a small portion of what's there.
If you like American history at all there are collections of just about anything you could think of in the museum.
Outside in the village there are historically significant buildings that have been moved there or been recreated. There is a full scale railroad that runs around the perimeter of the property that uses steam engines. A while back they built a roundhouse for storage and maintenance of the engines, complete with an old turntable.
There is enough to see there that you can easily spend a full day there and it's worth doing.