That’s very interesting, thank you - nice detective work! So, it looks like the cemetery may have been landscaped as early as the 1960s. That’s somewhat aggressive - some of the headstones were as recent as the 1930s... I wonder if the stones may have been moved to the municipal cemetery, as with the previous cohort from St Thomas’s that’s listed in the MIs (although there are no Victorian memorials still there it seems).
Thanks again.