I have NEVER seen a 486 with USB ports. I imagine if you had one with a PCI port, you could add a USB PCI Card. That adapter you sent a link to is for what looks like 68-pin SCSI, and his drive is probably DB25 or 50-pin or lord knows what else at that age. It's a 328MB SCSI drive. I don't know if I've even seen a SCSI drive at less than 1 or 2 GB and still knew what it was. We're talking ancient freakin history here. A&E dug up a mate to this baby next to the Sphinx.
MY reading of the Original Post was "get the data onto a Linux box"