import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,4,0))
r=w0.workplane(offset=-27/2).moveTo(40.5,25).box(19,50,27).union(w0.sketch().arc((-45,-5),(-14,-49),(-12,5)).arc((-23,-17),(-45,-5)).assemble().finalize().extrude(-12)).union(w0.sketch().arc((-39,-7),(-21,-18),(-14,-39)).segment((-4,-39)).segment((-4,-5)).segment((-39,-5)).close().assemble().finalize().extrude(19))