Chris, this topic has been discussed here before, so you might check the archives. Several Oday 23 owners have run control lines aft and posted photos, etc., which I've found helpful. I'm actually in the process of running my halyards to the cockpit of my Oday 23 (1983), something I've been considering since I bought her in 2006. Like you, we decided after a season or two that we'd like to be able to hoist the sails from the cockpit.
The biggest problem I've encountered is that it's a very tight squeeze to lead the line between the grab rail and the cabin top. The turning block has to be positioned just so near the forward-most upright of the grab rail. So I've been looking for a block with a very small footprint. On my boat at least, a deck organizer won't fit and allo the lines to run free back to the cockpit. (It seems from what I've seen that there is more room for this on older 23s.)
In any case, if and when I finish the job, I can post a photo or two. Others may chime in, since this seems to be something many owners have done. And few forum members (notably, Joe, who sails Trinkka) have argued against running the halyards aft.
Good luck.
Bob
