It looks identical to mine which is a Buhler Farm King.
I found that when using the scarifiers in the fully down position, the box blade wants to rotate when it hits a big obstacle such as a tree root or immovable rock. One time this caused the link bars supporting the back of the box blade to deform. I managed to mostly straighten them out by backing the bottom of the blade against a tree stump then included a stainless steel tie rod (see attached photo) to prevent the link bars from spreading and deforming. Haven't had problems since.