John,
I've come to the same conclusion:
It looks like something changed in the coding of the mid-March LOR tags. I've been talking with John W to chase down some details of those tags, since noone has seen pics of them (other than the tag being discussed here).
That's a good point - later LOR tags from big cars don't have extra codes on them that I know of. I've got some contacts that I'll confirm that with.