Don't render the id, instead put it in a new field (to_replace_id)
Don't render the id, instead put it in a new field (to_replace_id)

This should mean we always create a new AttachmentData object with the replacement file, and we can use the to_replace_id to manipulate the existing object to tell it that it's been replaced.

hotvulcan/whitehall,askl56/whitehall,ggoral/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,ggoral/whitehall,ggoral/whitehall,askl56/whitehall,alphagov/whitehall,alphagov/whitehall,alphagov/whitehall,ggoral/whitehall,robinwhittleton/whitehall,robinwhittleton/whitehall,alphagov/whitehall,YOTOV-LIMITED/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,hotvulcan/whitehall,askl56/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall,hotvulcan/whitehall,robinwhittleton/whitehall