Q: CMS SCSI External Hard Drive DIP configuration

Would that be the SCSI ID setting? Any SCSI ID from 1 to 6 can normally be used, as long as another device does not have the same ID. ID 7 would be reserved for the Macintosh computer itself, ID 0 (usually) for the internal hard drive. Could the information for a similar drive at http://www.artisantg.com/TestMeasurement/65450-2/CMS_Enhancements_SD60_External_ SCSI_Hard_Drive (found through a random web search) possibly be of some interest?

Yes, other SCSI hard drive enclosures do usually have a push-button or rotary switch with an ID window.

I am not familiar with this enclosure/drive, but the manual for similar drives (link above) appears to indicate that DIP switches are responsible for ID settings here.

Did your friend study the ID charts in the manual under the link above? For example, ID 6 appears to involve only the DIP switches 1(up), 2(up), 3(down) and 8(up), whereas DIP switches 4, 5, 6 and 7 are marked N/A. Sorry, but I do not know whether these charts are correct also for the enclosure/drive in question. Nor do I know what the purpose is for the four unused DIP switches (if at all connected).

You're welcome. Good luck! If necessary, do not hesitate to post other questions about the Macintosh LC III and SCSI devices. Also, your friend could possibly be interested in a utility like Mt. Everything (http://www.overnet.de/hhp/mte/).