Might be of some help
I have a boatyard, but don't have any C23T's around right now, but they were once sold out of this facility therefore I might have some product information that offers what you are looking for. The only thing is I am in Hawaii right now and can't check until I get back. But, I will try to remember. But, to best figure it out, if you cannot get exact measurements off of another boat, is to four point your mast with rope and get a few friends to help. Attach securely lines as a forestay, a backstay and two port and starboard sidestays. You might be able to use the main halyard for the backstay and the jib halyard for the forestay. Use a couple other lines (ropes) for side support and pull them all very nightly. You should have (I believe the correct size is) 5/32 1x19 SS rigging wire attached to the upper points at the top of the mast. I presume they will have eyes swaged for the fore and back stays and then maybe forks for the sidestays. You will have to check your masthead out and the attachment points for the upper side stays to determine which fittings should be used. Have your local rigger swage the right fittings on the tops and then make sure your cable is too long for each part. The upper shrouds should run through the spreader tips adn the lower shrouds should be attached at the spreader bases as well. Then get a few buddies to help step the mast as plumb as you can and tighten all the temporary lines to make sure the mast stays in place. You can retain your friends to make sure the mast stays put while you measure up the cables and you will need them to help get the mast down anyway. Measure up the lengths by having your turnbuckles attached to the backstay and all side stay chain plates and the one for the stemhead fitting at the bow. Open up the turnbuckes 3/4 of the way. I assume you will use a turnbuckle with a hollow stud for the wire to feed into. Stick the wire end down the turnbuckle and see how far it goes in before stopping. Measure the wire that will sit inside the stud and then use it to measure the outside of the stud so you can see from the outside how far down the shaft the wire will go for measuring purposes. I should have mentioned that you should have taped or attached a measuring tape to the mast to determine that it is plumb. You can measure from side to side to assure it is not leaning one way or the other and then with a plumb bob type use, see that it is fairly straight fore and aft. A slight rake to aft is acceptable. So, with the mast in proper position, have one of your buddies hold the turnbuckle up and the wire can be matched beside it so you can mark the wire with tape or a Sharpie magic marker where it should be cut. When you have all of the cable marked, pull down the mast and then take the rigging parts to your rigger to swage the turnbuckles onto the bottom end. Now reattach the finished cables to your mast, through the spreaders, etc and then hoist it up again. Of course you will have your backstay attached as well as your two upper shrouds before you raise it and then when up, you can attach the forestay to support it with at least 4 points. Then you can attach the lowers and tune it up. The adjustment that you allowed in the open turnbuckles when you did your measuring should be sufficient to properly tune your rig. Remember, if you get stays or cable from an older boat, they probably will have stretched through time and might be just too long enough for you to get proper tuning (the turnbuckle closes up too much or bottoms out). It might be a little inconvenient to drive to your local rigger more than once, but at least you know you are getting a product that will fit. Also keep in mind that some boats came with standard rigs and tall rigs. If you use stays from another boat, make sure the rigs are the same height. Even manufacturers use different sections through the years and while they are supposed to be the same in length, it isn't always the case. I am pretty sure LeFiell was the manufacturer for the mast section of your boat. They are still in business and you can replace your mast with the same if needed, but they won't have the measurements you are looking for. They will also have the boom section used on your boat if you ever need one of those. Good luck and happy sailing.
