Presto 7 Enabler v3.2.1, same version as the extension that causes the bus error. These are both what I received from Sonnet. So, looks like they may have mailed me software intended for the Presto Plus. Balls. As stated above, the system will not boot past happy Mac with this enabler in the system folder, so I think that's a strong suggestion it's the wrong one.

The card I have is stampe"Presto LC Sonnet Technologies copyright 1996" on the reverse of the board. The processor is XC68040RC25, so that's the 25Mhz version, right? From Googling it seems there were a couple of higher speeds, so maybe this is the earliest revision of the card.

Right, I need people to send me software. I found this post by olePigeon viewtopic.php?f=29&t=16397 . That's the same card as I have, dude can you send me the extension you have!