Not sure if there is an actual part number, but they haven't been available for quite some time, and the website has said 'purchasing temporarily disabled' for a long time. I think the guys here were saying the owner of the small company passed away.
So it looks like there will never be any new ones, the OBX were a copy of the TMH but they were discontinued well over a year ago.
For a bolt-in 98+ header I really seems we are all ****ed, until a ranger enthusiast with the means decides to start supplying a new TMH style repro for the community. No real companies are gonna start up making those complex headers for these old news expo swaps..
It sucks. I want to buy something as well, and have no desire to build a set.. For everyone in this situation the best temporary solution is to use the OEM cast versions as they are at least much better than the shitty OEM tubular junk some of the models had.