For a historical look at how the pitch of A varied from the 17th century until it was standardised in 1939 have a look at the list on this page: Standard Pitch. The ranges vary from just over 400 to about 455 (with one odd one at 309). (Even now, according to that article, some like their pianos tuned to A444 rather than A440 leading concert halls to hold 2 sets of pianos).

Mick