Hey Rico,
Original owner installed track on the rails on Lucky Dawg. See pictures in my posts here:
http://pearsonariel.org/discussion/showpost.php?p=15092&postcount=8
http://pearsonariel.org/discussion/showpost.php?p=15403&postcount=27
I think had I done it, I might have put a matching backing inside, but as I mention in the post, in 40+ years, it hasn't failed... Interestingly, that is the only sail track on LD - none forward.