import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,39,0))
r=w0.workplane(offset=-82/2).moveTo(7,-27.5).box(16,1,82).union(w0.sketch().arc((-42,4),(-23,32),(-32,-1)).arc((-18,43),(-42,4)).assemble().finalize().extrude(-3)).union(w0.workplane(offset=4/2).moveTo(18,-37).box(64,16,4))