abarron
Recovering from that scenario could be problematic, as your system is probably in an indeterminate state.
You may be able to troubleshoot it, try for 30 minutes (I would not waste any more time than that), but really if you are inexperienced then a reinstall & restore may be the quickest & easiest answer.
Is the text based server manager accessible ?
Login as root, type console,
or
login as admin
then select server manager,
move around with tab keys (or mouse if connected)
Try running the restore
Highly recommended for a variety of reasons, obtain a UPS (Uninterruptible Power Supply) & attach to your server & enable NUT (see Howto or Contrib wiki article), they are relatively cheap these days, make sure the model you choose is compatible with Linux/CentOS, & avoid power loss issues in the future.
Look in the log files
/var/log/.....
if you still cannot get text based server manager access.
eg
cat /var/log/filename
see messages & httpd logs
Was that gentle enough ?
This finishes and declares that all is clean so I try to open the web interface to server manager to start another restore and I am told it is unavailable
It is best to quote exact error messages, & look in the log files for specific errors & informative messages.