Please don't do this. We're talking about a serious amount of important data here. Spinrite is cool if you've nothing to lose but for something like this, its not a good way to go. Don't freeze it, don't swap the logic board and to be totally honest I would say don't even power the drive up when you get it.
It seems REALLY odd to me that a
single drive failure lead to the old site's demise. Furthermore its odd that the host sent you a single drive with the idea of being able to retrieve data from it. It should have been a RAID array. Perhaps it was just a mirror array and the controller or backplane took a dive, and the drives with it. Anyway, there's something the host isn't telling you, and hopefully you've changed hosts since. The question about how the backup(s) became corrupt is another interesting one too. Non-ECC RAM on the server has been know to garbage DB tables over time.
My 2c.....send the drive
directly to Kroll or another reputable company with a clean room and expertise. Once you get a quote, start a fundraiser and I'm sure many of us will chip in to bring that data back.
I've personally done software and hardware data recovery in the past, however before doing so I was very clear about the risks involved without having a clean room facility. In cases where the customer wasn't comfortable with the risk, I sent drives to CBL
http://www.cbldatarecovery.com/ I would highly reccomend them. No I'm not affiliated with them, other than having them recover data from electronically\physically nuked drives in the past.