import cadquery as cq
w0=cq.Workplane('YZ',origin=(29,0,0))
r=w0.sketch().segment((-17,-45),(50,-45)).segment((50,-9)).segment((3,-9)).arc((-31,42),(-17,-18)).close().assemble().push([(16.5,-27)]).rect(29,26,mode='s').finalize().extrude(-58)