Very nice cover, philb, a great find.
Do you think the double cancellation had anything to do with the use of the pre-cancelled stamp, or perhaps it was cancelled again in Montreal because of the address correction?
I believe that it is addressed to Madame
Rose de Lima Lavalee.
BTW, St. Rose of Lima has been featured on a number of stamps of Peru, including this airmail from 1936:

--Kevin