import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,26))
r=w0.sketch().arc((-49,43),(-39,39),(-48,44)).segment((-48,43)).close().assemble().finalize().extrude(-54).union(w0.sketch().arc((7,-33),(23,-34),(37,-45)).segment((50,-45)).segment((50,6)).segment((19,6)).segment((19,-27)).segment((7,-27)).close().assemble().finalize().extrude(3))