OK, so I bought a used 630 and got it activated (I wanted a second one anyway). It's nice to be able to record stuff again. I'd still like to get the old one back on the air myself with a bigger drive if I can.
So I thought I would use the eSATA case and my existing 1Tb drives to see if this box would work with an external drive. With the power off on the eSATA case, I put the hard drive in, plug the cable into the 630, and then power up the eSATA case. And nothing happened. What I had to do was to unplug the 630 and let it reboot with the eSATA enclosure powered on. With both drives, I got an offer to format them, and did that. I took the Samsung SSD and put it in the dead 630, and it accepted the drive and is a PVR again! :-)
So it looks like the 56.05 firmware is no longer able to format drives without a working drive in place, but its good news that you can do this on another 630. I am happy :-)