My Capri 14.2 has a "Capri Sails" sail.
The upper batten measures:
5/8" wide x 18" long x 1/16" thick.
You might check with Catalina Sails to see if they can help, but you should
be able to measure the remaining two battens and come up with the width
and thickness you need. Measure the batten pocket and subtract a bit to
allow the new one to fit properly. (Similar to the fit of the other two.)
After I posted the original note it occurred to me that I had a 5/8" batten from another boat that could be used as a replacement. Some measuring, cutting and smoothing and all the pockets are full again.