import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-2,0))
r=w0.sketch().arc((-3,15),(5,2),(7,-14)).arc((15,5),(-3,15)).assemble().finalize().extrude(-48).union(w0.sketch().segment((-28,40),(-25,30)).segment((8,30)).segment((2,49)).close().assemble().reset().face(w0.sketch().segment((-8,-30),(-2,-49)).segment((28,-40)).segment((25,-30)).close().assemble()).finalize().extrude(52))