Okay
Bleach 190 page 19 | One Manga
it is at his neck in this picture, clearly at his neck as well, so don't say its always been at his sternum
Also note how much his hollow mask is torn, this could merely be to time consuming for the artist but, it becomes more straight in the current manga
(this of for mask)
Bleach 340 page 12 | One Manga
(for hole)
Bleach 341 page 11 | One Manga
not really much a change, but from what i understood hollow holes stayed totally in place... i dunno though ^^