When I had called Browning Headquarters in Missouri I wasn't really given the time of day, and was told to call Browning Canada in Montreal.
So I did that on Wednesday of this week [2 days ago]. A fellow by the name of Carl said that he would try to find a replacement carbon fiber stock in the US if he could. He didn't think it was likely to find one, because these are a limited edition run. If a replacement stock couldn't be found, then he was talking about all the other less desireable options I mentioned above.
So I just got off the phone again with Carl at Browning Canada's headquarters, and he said that he did find one, and it is ordered, and is to be shipped to Bashaw Sports [the nearest certified Browing repair shop to Calgary]. The stock is to be replaced by them under warranty, I just have to send in my rifle to get that done.
I'm pretty happy that they were able to find a replacement stock. I guess I was lucky. I hope this new stock doesn't have the same problem down the line. Next time I'm sure I'll be out of luck!
Thanks to everyone who gave ideas and offered help. It's much appreciated.