OK UPDATE - ITS WORKING

Sorry to have overlooked a crucial step. When you log into the Blockchain website they display a QR string next to your wallet. Silly me thinking this was the one to scan, but the steps on the mobile app make it clear to go into your account and click 'Devices' to display the QR string. Once I did that, I got a new QR string and the mobile app recognized it and now it seems my (empty) wallet is showing on the mobile app.

Thanks for the tips & your patience. Hopefully some other newb will find this and not be tripped up like I was.

Moral of the story: When in doubt, read the instructions