Thanks for sharing this story.
I'm not 100% sure I picture how far out on the CB you were. Because of the crack, I imagine you might have stayed close to the hull. People who report being able to right their boats had to stand pretty far back (and may have had an extra 100 lbs on you).
For a replacement CB you could advertise here in the WTB section to see if anyone has a spare one (make sure to note it's for a DSII) or you can purchase a new stock one from D&R Marine.
You may be in a better position to evaluate whether the crack can possibly be fixed. Is it a matter of simply grinding back the laminate and patching the crack?
Finally, people have made their own by gluing strips of wood into a plank, then planing and sanding that into a foil profile. Here's an article that describes the process of
how to build your own centerboard.
(If you plan to race your boat in DSA sponsored races, you need to read and follows a few simple prescriptions in the DSA bylaws to makes sure your CB remains class legal, if not, you don't have to worry).
Advantage of building your own is that you can give it a much better foil profile than the stock design; it's a skill you can master, but it may not be for everyone.
Advantage of repair (if feasible) or getting a used one would be price.
Advantage of getting a new one may be in getting back on the water the fastest.
(Spreaders are available from DRMarine as well).