Nuendo 8.1 and PT control legacy app version required.

Is there anyone out there using 8.1 with an s3 Protools dock and ipad. Our ipad got on the internet and updated the PT control app.
We have managed to roll back to PT control version 18.3. But that is compatible with 8.3.
For some reason I can not remember this studio will not update too 8.3. Hence the old version.

Windows 10 and Nuendo 10 being installed soon. But need this until then.

Any assistance gratefully received. Also how to roll back an ipad app version guidance welcome.