WD AV-GP 2TB is the model of a couple of the guys here have installed in their boxes, as for current recordings I’m not entirely sure they can be transferred over to the new hard drive.
The recording partition is on an encrypted filing system.
I replaced my HD as well and wondered what the unit would make of the original disk in a caddy.
It sees the user partition and files where imported content is stored. It however does not try to mount support for the encrypted recordings partition.