Not recognized at probably excludes the possibility it appeared in the "PCI Adpater ID" section of an hinv -vm or in the output of a run against the L1 PCI command. On the odd chance it made an appearance in either location (and the even less likely possibility you haven't already btdt), it might be interesting to try again with the DVS software development kit.
If you don't already have it, devv was kind enough to link the DVS SDK in this thread
DVS has kindly provided a link to file named sdk2.7p28.tar.Z.
I believe this filename "sdk2.7p28.tar.Z" is more correct than "sdio-sdk2.7p28.tar.gz" (the filename that was previously reported in the forums) because this SDK seems to have support for SDStationOEM, HDStationOEM and Centaurus boards.
(All three are PCI-X boards, and according to http://web.archive.org/web/201604131846 ... chive.html
, Centaurus combines the features of SDBoard and HDBoard).
The top of the SDK README states "This is a combined Beta SDK release for SDBoard / Centaurus".
Probably a long shot, but the photos the OP posted of the board appear to match the "Centaurus" photo in the archive.org copy of DVS page devv linked in his post. There's an even better resolution photo of the board in the DVS Centaurus pdf file.