Does it exist somewhere?
I'm not after a site showing me all notes for the complete patch history, I'd be interested in a place that shows changes made to specific champions/items only throughout time.

Thanks in advance

mmm the best thing i can do is tell you would be to browse through the patch release notes for changes in your champion.

would be nice if mobafire or league craft offered something like this to go with build info so people could offer more insight as to the state of a champ at the time of the guide or build.

some champions here got their patch history.
Like Twisted Fate
Hope it helped u out.