import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-12,0))
r=w0.sketch().arc((-25,-4),(-40,-38),(-21,-6)).arc((-24,-8),(-25,-4)).assemble().finalize().extrude(12).union(w0.workplane(offset=24/2).moveTo(39.5,14.5).box(21,51,24))