import cadquery as cq
w0=cq.Workplane('YZ',origin=(0,0,0))
r=w0.workplane(offset=-46/2).moveTo(-8.5,-3).box(55,66,46).union(w0.sketch().push([(-19.5,12)]).rect(61,10).push([(-20,12)]).circle(1,mode='s').push([(47.5,15.5)]).rect(5,41).finalize().extrude(47))