USPS. Houston Division. First Day of Issue Ceremony Invitation (form letter) to the dedication of Scott #2578 29c Traditional Christmas Stamp - Antoniazzo Romano's Madonna and Child with Donor, FDOI, October 17, 1991, Houston, Texas.  Ceremony held at the Museum of Fine Arts. Houston. This form letter (printed signature) invitation was originally folded to fit a #10 envelope (not included). Apparently taken to the ceremony to be stamped and cancelled, the invitation has numerous creases and dings.  Invitation measures 8 1/2" x 11".