How can I delete a project/deployment on an old account I can no longer access?

There's a live deployment on an old Vercel account I can no longer log into (a leftover
from a past migration). My active project is on a different account I do control.

Since I can't access the old account, I can't delete that project myself. What's the
correct way to have an orphaned deployment taken offline and deleted, and the
default *.vercel.app subdomain freed?

I can verify ownership privately if needed. Thanks!

If you need help regaining access to your old account, please use the account recovery form at vercel.com/accountrecovery. That will open a ticket with the team with specialized tools to help with account verification and recovery.