import cadquery as cq
w0=cq.Workplane('YZ',origin=(-1,0,0))
r=w0.workplane(offset=-49/2).box(92,12,49).union(w0.workplane(offset=35/2).box(12,56,35)).union(w0.sketch().segment((-12,-27),(12,-27)).segment((12,-6)).arc((13,0),(12,6)).segment((12,27)).segment((-12,27)).segment((-12,6)).arc((-13,0),(-12,-5)).segment((-1,-4)).segment((0,-12)).segment((-12,-13)).close().assemble().finalize().extrude(51))