Rob at Black Dog Marine recently had to source one in double quick time, might be worth a call. Can't see you getting one in less than a week though.
What's up with yours?
Looking into the future, I believe there's a good chance your port (counter rotating) gearbox may suffer premature failure. Something to do with thrust on the bearings pushing the wrong way? You could pre-emptively get a recon box from USA, would save you a fortune (dread to think what a Verado box costs retail
), and prevent any delays at the me time.