I lost a couple of these screw-type sail stops ...http://www.sailrite.com/core/media/media.nl?id=2212&c=603010&h=85378b933d72b107b3f5
Last autumn, I drilled a 3/16" hole through my sail track, at the upper side of the luff-rope notch; just far enough up that the slug (slide) can't fall out of the notch. I can thread a quick-pin through it, or a zip-tie, or even a short length of 3/16" cord secured with a square knot (very cheap and easy to replace!)
My one slight disappointment with my new-last-spring KH 2000 mainsail is that it would have been better to space each of those bottom two slugs halfway between the reefing cringles, so I could pull in a reef without having to drop those slugs out of the track. (Hint, hint, Art.)
When Doyle Chesapeake built my new Stack Pack, Chuck O'Malley (the manager) asked me for the height of my headboard above the gooseneck - with the sail-stop in and all the slugs stacked atop the sail-stop. He made the cover to fit that measurement, so I can leave the stop tied in when I cover the sail. I can also drop the slugs out of the track with the sail in the cover, zip up the mast-end over the folded luff, and store the main in the Stack Pack - on, or off, the boom.