I wouldn't trust the 23 and it's mast to go up and try to attach it. I'd absolutely drop the mast.
Not sure if all brands of mast are the same, but mine has a mast crane that sticks out maybe 6 inches to the rear. If I recall there's a clevis pin through the crane that you can attach the TL to. I'd recommend an adjustable setup since the 23 has 3 sheaves and jam cleats in the boom, one of which is for the TL. The others are for the out haul and reefing.
You could simply run a roughly 1/4 in line from the mast crane to the sheave in the boom, forward through the boom and out the front through the jam cleats. This lets you adjust it if you go forward. Should be loosened after raising main so boom is supported by the sail, then tightened to support the boom when sail is down.
The main drawback of this is that if you remove the boom for the winter and store it you have to pull the line out of the boom before you unstep the mast, this you have to later thread it back through the boom, like with an electrician fish tape.
Look in the owner mods section here, but in brief the approach I used is: I left what had been a fixed stainless wire (about 1/16 diam) TL on the crane, but shortened it so it was about 3 feet short of the boom end with boom horizontal. Attached a thimble to the lower end. Attached a small swivel block to the thimble. TL line runs through jam cleat into front of boom then out rear over sheave, then up to and through block, and back down to be tied off with bowline to casting at end of boom. This lets you adjust TL with 2:1 mechanical advantage. To remove boom you only have to untie the bowline and pull the line through the block, but leave line in the boom.
Others who like to adjust it from the cockpit have added a small horn or other clear to any end of boom and tie off the line to this.
