Phil,
There is something not quiet clear with the photo )37.89 posted by Baz !!!
If your assumption is correct;that it is prior fly over,then the background to the photo should have been the houses on the corner of Bedford rd and not Dowding and Mills.
These houses and the top of Bordsley station can be seen clearly in your photo (50.66 kB
Dowding and Mills was 100 yards further up the hill towards Bradford st.