Initializing will wipe it out, so don't.
I don't know if you are comfortable with this, but if it were me I would think about taking the drive and hooking it up inside a desktop PC.
There is always the possibility the drive is going bad; what made you want to restore to initial setup?
Update: By following the specific startup/connection sequence found on the Vantec FAQ, I am now able to see the laptop drive!! The key for me, was to shut it all down, restart the PC. Power up the USB connected drive before connecting it, and then connnecting the USB cable from the adapter to the desktop computer after a minute.
Thanks for all the advice!