Well, Merlin is an amazing help!
I called him as suggested, and he was able to find 3 of the 4 parts through their "OE Connetction" part inventory service. In five minutes, he managed to do more than my dealer's parts manager has gotten done in 3 weeks. I'll give my dealer the benefit of the doubt on this point for the time being - maybe they do not subscribe to this service.
Secondly, he had me check to make sure that my dealer's part order was properly upgraded to "Customer Care" status with my VIN (meaning I'm waiting for it). I'm not sure that this was done, either.
Third, he had me call Isuzu Customer Service as an additional shake-the-tree measure. That's when things got confusing - the service rep said that he was showing those parts available, and he did not know why the dealerships were showing them unavailable.
I sent the part numbers to Jerry, but he hasn't gotten back to me yet. I'm still in need to the cage assembly, which doesn't seem to be available anywhere.
PS - Thanks for the info on the paint job, Weasel. I saw that thread a few weeks back but never read it, since I thought it was sacrilegious!! Now I see what great taste you have, and so all is forgiven. :-)