Personally I'd abort HDD Regen -- if it hasn't made more progress in 31 hours it's not likely to have any notable success with that drive.
I'd start experimenting with partitions -- create a 44GB one to start, then see if it formats okay.
If so, then create a 10GB "BadArea1" partition (but don't format it); and then a 3rd partition that uses the rest of the disk. If the 3rd partition formats okay, you're done unless you want to experiment with just how big "BadArea1" needs to be. If that's the case, delete the 3rd partition and delete BadArea1; re-create a "BadArea1" partition but make it smaller (perhaps 5GB); then make another partition after it and see if it formats okay. You can repeat this process until you isolate just how big "BadArea1" has to be.
If you map out the area with physically damaged sectors, it's not likely to spread to the other partitions as long as they're not on the same physical cylinder -- which is VERY unlikely unless your "BadArea1" partition was exactly the right size down to the last actual sector (almost impossible).