Dear Andy,
I hope you received your letter of recommendation from Dad. Please let me know if not, and I'll help Dad sign and send another.
May I ask you also to consider this nomination for dad, below? I sent U of C a letter, but I think nomination letters from friends, colleagues, and former students will carry their own weight. Perhaps you could also send this idea along to the Confessing Christ group, some of whom I believe might be moved to send their own letters. The process is very simple and described at the link they provide.