Twin was a DOS based spreadsheet program from Mosaic Software, Inc. that was judged too similar to Lotus 1 2 3. Both predated Microsoft Excel which cannot open Twin files as you have already discovered. Twin files have the same .wks extension as Microsoft Works files but they are not the same format.
I still have a working copy of Twin and I can translate your Twin .wks files to .dif that most spreadsheet programs can import.
Rates are $100 per hour with a minimum of 2.5 hours charged.
I accept payment via paypal for emailed files.
Personal or business checks are okay for files sent on CD/DVD disks or other mailable media.
Contact me if you need the service.
