import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-18,0))
r=w0.workplane(offset=-17/2).moveTo(-4,-1).cylinder(17,11).union(w0.sketch().push([(-15.5,-26.5)]).rect(29,47).reset().face(w0.sketch().segment((-29,-27),(-25,-36)).segment((-12,-30)).arc((-6,-33),(-3,-27)).segment((-2,-26)).segment((-5,-17)).close().assemble(),mode='s').finalize().extrude(18)).union(w0.sketch().push([(-15.5,-26.5)]).rect(27,11).push([(-27,-27)]).circle(1,mode='s').push([(12,32)]).circle(18).finalize().extrude(53))