Dexter Axle has a listing of industry part numbers for wheel bearings that fit their brake drums. Many older Airstreams run with Dexter brake drums, especially the 12x2 six bolt.
Here is a link to thier website.
I figured someone out there may need to know the four industry part numbers for the four members of our wheel bearings; cups and cones, big inner and small outer. With the industry part number, you can go to your favorite auto parts store and order a set for your coach.
I hope this is helpful information.