Here's the serial on my Oyster with that same funny first digit "2"?
Haven't seen an explanation of it, but I've seen it in other Oysters of that period.
With all the Canadian Oysters, there are so many variations you could write a book just about these wartime Oysters.
Oops. You can't see the serial very well here. But you can see the smaller first number on the left end.
Oyster3.jpg