Any way to get credit for publications that I drafted as a fellow for a law professor?
What you are describing is actually ethical misconduct. If you were the primary drafter of an article, then you should have been listed as an author on those papers; the fact that you have not is inexcusable on the part of the professor. In the scientific world, such a revelation coming to light would be sufficient grounds for retraction of the articles in question.

So right now, the problem is that if you try to claim ownership, you may be creating a lot of problems. I don't know what the right solution is, but you should definitely talk with someone at your law school such as an ombudsperson before talking to your advisor. The last thing you need right now is having a former advisor who can "spike" letters of recommendation.