Well that was quick and painless, unlike the CLT baggage office. Sent in the receipt ($119.19) yesterday, with just a single line item (I didn't feel like itemizing socks...) and got an approval today:
Thank you for contacting American Airlines and for your loyalty as an AAdvantage Executive PlatinumŽ member. This letter is to acknowledge receipt of your recent correspondence. I appreciate the opportunity to respond to you.
On behalf of American Airlines, please accept our apology for the delayed baggage when you traveled with us to Portland, ME. I’m sorry that we delivered anything less than a wonderful experience while traveling with American. I can assure you that this experience is not typical of our usual performance.
Although I cannot change what happened, I'm happy to let you know I've resolved your claim in the amount of $119.19. You should receive your check within 30 days at the following address...