The key to the NOL is to take your time and go over the worksheet line by line. I always pull up the instructions to guide me because, as you say, we don't do these every day.
Most NOLs are not as involved as Helow's which was due to the client procrastinating and losing the option of going forward rather than carrying back. I don't like carrybacks because it usually opens up a can of worms for the IRS to question.
taxbilly