So I spoke to a nice guy at Hayes-Lemmerz and he told me that those flat orange wheel seals did not come on their wheels from the factory. They use the dark red o-rings during assembly. I asked him if he knows where those flat seals came from and he said they are available through Hutchinson. I'm not going to buy a set right now, but it's nice to know they're available.
1985 M998 HMMWV w/ 6BT Cummins