import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,17,0))
r=w0.workplane(offset=-65/2).moveTo(-31,-6).box(38,78,65).union(w0.sketch().push([(9,29)]).rect(82,32).push([(-29.5,35)]).rect(5,4,mode='s').finalize().extrude(30))