Hi There
I've often wondered the same thing but as I never had any family's BMD's there I never followed it up.
All google results show that there are records for St. Andrew's going back to the early 1700's YET all building references to St. Andrew's relate to Westland Row and the 1832 / 1834 / 1837 dates.
I can only presume that the 1832 building was to replace an earlier building yet I can't find a reference
If I find something I shall post it !
Tara