If the 23.5 is like my 240 it has a molded slot in front of the anchor locker to fit an anchor roller- have you considered adding a roller instead of a rail hanger? It helps a lot when retrieving the anchor, and the anchor stores on the roller. It is more work to install- you need to drill and tap 3 bolt holes- my 240 had an aluminum plate molded in the slot for this purpose, but you can also access from below to use washers/nuts. I used a Windline URM-2 roller (2" channel width), I think that will fit the 23.5 also.