One of my sails, a Saintoge has this system. The battens do have caps similar to a windsurfer. While using it with out the caps will work I don't think you'll get any warranty service if batten wears through the strap. I think Mystere still uses this system on their new sails so you might have luck finding them there or just call Calvert and get the right thing.

Nothing like new sails. Enjoy!