import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,19))
r=w0.workplane(offset=-38/2).moveTo(49.5,18.5).box(1,15,38).union(w0.sketch().segment((-30,-16),(-27,6)).arc((-49,-16),(-19,-17)).close().assemble().finalize().extrude(-7))