Thanks to all of you for the excellent explanations. It's getting a lot clearer in my mind now. I checked today and I have an open clutch, block at the base of the mast, and the starboard side of the boom is open for what should work out to be a parallel version of reef #1. I also found a picture of the carbo blocks via a google search and can now visualize the benefits of that (easier to pull, AND it keeps the line on one side for each of the reefs).
I'm unclear how to run the new reefing line through the boom, but Sailfanatic's clue about removing the end caps of the boom should get me headed in the right direction. I'll try to figure that out more as I wait for the fish tape to arrive.
The slugs/jack lines discussion is still foggy, but I'll wait for a calm day, raise the main and see what I'm working with. I have only put reef #1 in once (and have left it there because it's been really windy lately) and we definitely had to winch it down to get the clew to come down. I'll play with it on the dock in the spirit of Jssailem's Navy Seal quote. With reef #1 in I don't see any tension on the slugs, but I'll take some pictures and see what ya'll have to say.
I also have the slug stop above the feed hole that Valor mentions, and had the same thing (slug stop) on my Catalina 22. On the 22 I found a mast gate for the feed hole that prevented the slugs from coming out, and loved it. Has anyone put a mast gate on a 310 and removed the slug stopper to let them run free without popping out?
I'll re-read your posts while at the boat and see if I can get some pics that help move this along.