hummmm
I think I get what you're saying ... so they would maybe remove first head stone and make a new one with a new name added? or keep the old one and add a name ... ?
Nathaniel bc 1827 ..died march q 1911, Mile End Old Town
Nathaniel bc 1858 died march q 1911, St Pancras
Sarah Bryceson bc 1826 died Dec q 1890, Islington
Sarah Clark Bryceson died sept q 1855, Islington
Mary Ward Bryceson died June q 1865, Islington
there were other children but can't remember ...late here

i wonder if they are all there?
deb