You can download all the pertinent parts lists from Dometic. I started to order a second wire shelf for my RM8551 direct from Dometic, but it was outrageously expensive...well over $100 as I recall, before shipping, and non-refundable if I blew it in ordering the right part. They suggested I could also obtain it from an authorized dealer, but the authorized dealer here in town would have had to order it, and then add their mark-up. My plan was to replace the plastic bin, but I'll be waiting a while longer.
2009 Tacoma Crew Cab, TRD 4WD
2007 Tundra Double Cab TRD 4WD
2014 Escape 19
2007 Norwegian Elkhound "Baxter"