Yet in some cases this would be very useful to be able to do. For instance, Manfred Kuehns blog was discontinued in 2018, and more recently removed entirely from Blogspot where it was hosted. The archived versions are the only current source for those blogpostings. This means there is no ‘original’ page online anymore to gather the annotations around.
I see Chris Aldrich has annotated posts from that same weblog by Kuehn, maybe he can shed some light on it.