Lorenzo from NYCE distribution may have some in stock. I got mine from him.
I would like to know what software you have that requires it, since AFAIK IBM never really published any apart from the diagnostics. You were expected to develop your own and my memory is that almost nobody bothered.
not my auction, but apparently several folks are looking for this -- https://www.ebay.com/itm/154376047918
I intend to, I should get it next week