Sorry for the delay, folks. I have been super busy since Atlanta and have not had enough free time to post.
Most of the rest of the saga is detailed in my latest blog post, along with a brief report from the rally, here:http://ourodyssey.blogspot.com/2011/10/waiting-to-get-my-bearings-in.html
As I suspected, and notwithstanding several comments here to the contrary, the bearings are not available in North America. They do not cross to anything domestic. More than one bearing house told me they could get the direct replacements, but they would have to come from overseas. As a product importation, they would be subject to duty and likely a three or four day delay in US customs. One supplier said a $40 bearing could easily become a $400 bearing that way.
On top of that, the outer bearing was a Japanese item from Koyo, and it is so old that Koyo no longer has it in their computer nor do they have a spec sheet. Presumably Mercedes switched suppliers at some point, and I will be interested in seeing if the replacement item is a FAG, who made the inner bearing.
I ended up ordering two bearing sets and four seals from my supplier in the UK. He should have them tomorrow and will overnight them to me on DHL. Unless they get hung up in customs I should have them Friday. The bearing sets were around $600 for the pair and the seals are another $50 or so, before shipping. I am guessing another $200 for shipping making the parts alone just shy of a "bus unit." I'm going to have Joel repack the other three, and if he finds a marginal one we will have a replacement on hand. In either case I will end up with a serviceable spare.
Thanks for all the help. I'll be posting the progress pictures on the blog once we have the parts.