Contacted Customer Service through e-mail and got a quick response. Ordering was easy through website.
Back panel - left - for: ada/asa/aua7112
Back panel - left - for: ada/asa/aua7112 wet section (22 1/4 x 34 9/32) o/s wj10al & wj9bl
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.