You may want to consider a replacement speedometer gauge face from Raceratb.com as an inexpensive and effective alternative while you go through the effort of obtaining a new cable. Mine's now accurate within 2% and it keeps your speedometer and odometer in sync, assuming that you're using stock DL1000 sprockets.
New one's on the left, stocker is on the right. Save the Speedo-Healer for when you change your gearing. With Austin's replacement gauge face your speed and mileage will both stay accurate when the Speedo-Healer works its electronic magic.

New one's on the left, stocker is on the right. Save the Speedo-Healer for when you change your gearing. With Austin's replacement gauge face your speed and mileage will both stay accurate when the Speedo-Healer works its electronic magic.