You might check with the door and window supplier. Their name is on a sticker on the window and door, and as I recall their business is located in Vancouver, Canada.
I had a window lock fail a couple of years ago, called them and found they had all the locks in stock and readily available, even down to the color. Cost was quite reasonable.
I think they also sent me a couple replacements using the 'trust' method, that is, I would send them a check after the parts arrived. Nice.