sent a postcard, SASE and a birthday card with separate envelope addressed to my mother with a separate postcard explaining that Mom's milestone birthday is coming up. Mailed on 12/24/2015.
Address I used was:
405 E 54th Street
Suite 12D
New York, NY 10022-5123
Received word from Mom that around 1/15/2016 she received the card and an autographed Playbill.