I wrote an answer on Stack Overflow. It then got migrated to Super User, where I got some credit for it, then here. However, I don't see the 470 rep that it should have generated.
Is there any way for me to retrieve it?
You don't have an account on Super User so it looks like that lost the associations. Create an account and associate it with your existing accounts. This should give you ownership of the answer on Super User.
If that doesn't give you ownership here (I'm not certain that it will) then either let me know and I'll contact the team or you can e-mail them directly at the "contact us" link on any page.