Looks like an old IDC50 connector. You're not going to find a USB convertor for that.
http://www.laluna.co.uk/scsi_info.phpYou're probably going to have to ditch the USB idea and look for an older SCSI card that will be compatible with the drive directly and the PC you want to use it in.
I dbout the data will be in a standard format anyway so you may not be able to read the drive even if you do connect it up.