Get a PCI SCSI 68 pin card. If neither of you has a cheap PC to put it in. Get a cheap used one off eBay with Windows already installed. It'll be cheaper than a used SCSI to USB adapter for the Macbook. You can use other SCSI cards but will have to also deal with adapters and may not find drivers.
If the disc is Mac formatted. Use a program like HFS Explorer to read the contents or paid options for read/write.
Also if the disk is Mac Formatted. You can try to find a cheap vintage Mac with SCSI support. You might find a Mac II line, Performa, LC, Centris or Quadra for under $100. Perhaps one of the early Power Macintoshes. Basically any beige Mac has SCSI support and will just need a 68 pin adapter. You can check EveryMac.com for a...