import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,-4))
w1=cq.Workplane('YZ',origin=(0,0,0))
r=w0.workplane(offset=54/2).moveTo(31,21).cylinder(54,7).union(w1.sketch().segment((-36,-50),(-9,-50)).segment((-9,-25)).arc((-7,-17),(-9,-11)).segment((-9,2)).arc((35,29),(-14,14)).segment((-36,14)).segment((-36,-11)).arc((-37,-17),(-36,-25)).close().assemble().finalize().extrude(-39))